it's been a long time but I've been busy with irl stuff, plus I managed to actually watch the movie so I think I can address this now
I don't remember what I said back in October so pretend that my argument is just based off of this comment, I'm too lazy to reread the entire thread
Gohan was only able to kill Cell Max after Cell Max had already gone through several handicaps to his power
1. He started out with Broly level power once he was activated, with his only incompletions being his personality and mind
2. He took several attacks to his weak point, to the extent that Fat Gotenks could crack it (could be PiS but it at least makes it clear that his weak point is much weaker than the rest of his body. At most it's as durable as Ultimate Piccolo cuz he also cracked it)
3. He got his arm blown off by Gamma 2 plus half his body petrified
4. He got mildly pummeled by Orange Piccolo who, even thought he was weaker, could still beat up Cell Max, and was able to retrain him for pretty much a full minute until Gohan finished charging the Special Beam Cannon
(side note can I just say how stupid that scene was like wtf why did it take so long to charge the attack like bruh cmon man it took like 5675432765432 years for Gohan to launch that tiny little beam bro why bruh)
Cell Max was far weaker than his released state at this point, to the point that an exhausted Orange Piccolo could stack up against him somewhat
Orange Piccolo is stated to be on par with Goku and Vegeta individually in their SSGSS states at this point, who are unquantifiably superior to their Broly Movie states
Ikari Broly alone was already capable of handling SSGSS Goku, meaning when he stacks Super Saiyan, he should be at bare minimum far superior to twice as strong as Goku or Vegeta. I'm only saying this because ik a lot of people don't agree with the whole "SSJ is x50 stronger than Base" argument, so I'm generously lowballing it to x2 since Broly no sold Goku's and Vegeta's Galick Kamehameha simultaneously. anyways moving on
After Goku and Vegeta lose horribly, they escape and fuse after an hour, meaning Ikari SSJ Broly has an hour's worth of time to RE and get stronger against Frieza, which is shown pretty clearly. When Frieza turns Golden at first, Ikari SSJ Broly is visibly pushed back and surprised by Frieza's power boost, but then after half an hour he's seen pummeling Golden Frieza with the same ease as he did Base Frieza from before. Plus, it's his entire gimmick to keep getting stronger as the fight goes on. So Ikari SSJ Broly becomes unquantifiably stronger
After Goku and Vegeta successfully fuse against Gogeta, who is far superior to SSGSS Goku and Vegeta individually, Ikari SSJ Broly could keep up with SSJ Gogeta, who scales slightly above GGA Broly at this point
Ikari SSJ Broly unlocks LSSJ and bodies SSJ Gogeta, who responds in kind with SSGSS, with Gogeta then dominating Ikari LSSJ Broly
so let's put it like this
SSGSS Gogeta > Ikari LSSJ Broly >>> SSJ Gogeta > Post Frieza SSJ Broly > Pre-Frieza Ikari SSJ Broly >> Base Gogeta > SSGSS Goku or Vegeta
So basically TLDR Broly at his best is way more than just a Super Saiyan Blue level difference compared to Super Saiyan Blue Goku in the Broly Movie
which is ******* ridiculous
But also TLDR, Orange Piccolo is only a little stronger than Broly Movie Goku and Vegeta
and weakened Cell Max is only a little stronger than Orange Piccolo
Gohan's best feat is killing Cell Max, who not only had 4 handicaps at this point as I listed above, but it was also a direct hit to his weak point which is weak enough that fodder characters can harm it and Ultimate Piccolo can crack it, ALSO Gohan uses the Special Beam Cannon which drastically increases his normal AP
TLDR meaning that Gohan needed Cell Max to be weakened in 4 separate ways, target a weak spot, AND damage boost himself to immense levels to kill someone who's not much stronger than Broly Movie Goku and Vegeta
That's not looking good for Gohan at all.
Also, as for the "sadism weakness" that Gohan doesn't have anymore, no, he still has it. He stood there and took an attack, kicked Cell Max across the field, and gave a pretty obvious evil smirk. He only initiated the Special Beam Cannon after Piccolo yelled at Gohan to get his ass moving. So Gohan should have all of the mental weaknesses as his Cell Saga state, if not slightly mitigated
Orange Piccolo is not SSB Level. He's distinctly above it. Orange Piccolo is a form that is stated to be able to keep of with "Goku and Co's" strongest/They are on par now, at least according to Toriyama. So it would be the level above SSB in the form of UE/UI, or at LEAST SSBKK and SSBE since the film was being developed vastly before UE and PUI/TUI came out. (Though the interview happened after the actual films RELEASE, so for all intents and purposes you can easily assume he meant UE and UI, as well as SH Movie Broly, not DBS: Broly.) This in itself is supported by the fact that DBS:SH takes place after Granolah, so the "strongest battle" (according to the information given from the East), occurred after Black Frieza. It's also supported by the fact that Piccolo establishes that each Gamma is Goku and Vegeta level
in the film. Again, referring to what he SHOULD know, that means they were at LEAST SSB level, and his knowledge would cover their Moro Arc selves. Ultimate/Awakened Piccolo fought pretty comparably to Gamma 2, so if anything it's Ultimate Piccolo who is SSB level, and Orange Piccolo as higher.
Even if you were to assume the worst, Orange Piccolo would be stronger than a SSB Goku and Vegeta. (And again, considering the interview occurred after the film, you could reasonably assume Toriyama's on par was about Goku and Vegeta's peak in Granolah, not Broly.)
1) Cell Max's power level is pretty wonky. He's established to be an opponent not even Broly could beat had he been completed, but he doesn't have physical incompletion, only mental, so I presume this merely means Broly is comparable, and Cell Max's feral mind limits him from using his power at a higher level, like how SSJ Berserk was weaker than the SSJ Berserk (Controlled State) for Kale, despite Kale only just gaining a handle on the power up.
2) Taking attacks to his weak point wasn't established to make him weaker? It's just the simple easy to whack boss battle weak spot. He even starts to fire more attacks and gets more frantic with his movements, so you could reasonably assume he just was hurt.
3) He did lose his arm, but as we know in Cell Saga, and in the Future Trunks timeline, whilst losing your arm can in itself weaken your PL, Teen Gohan and Future Gohan also display that with proper control and usage of your Ki you can still manifest your entire power throughout the rest of your body. (This is why Gohan can say "I lost 50% of my power..." by losing his arm and then can full on power blast SP Cell to death, which is eerily identical to how Cell Max behaves with his power sphere, losing an arm and then forcing all of his power into one hand for a final saving grace attack.) Also, Cell Max wasn't petrified. The grey is the paint having come off, as despite his classification as a "Bio-Android," and claimed by Hedo to be "Made will Cells," his body looks and acts like the Gammas, with it being wired on the inside and requiring a paint job on release, as his body is actually just grey.
4) This is true, Piccolo was able to hold out against Cell Max, but the film makes it clear the difference between them was not mild or minimal. He was getting beat around and given a dedicated scene to "die" in because he was THAT beat down. And whilst he did hold down Cell Max, this is the same series where Goku's grip on Frieza didn't get broken despite the tyrant putting more power in it to escape, or if you want to include GT, Goku was able to hold down Omega Shenron and attempt self destruct without the ability to get thrown off, (same with Super 17). This also occurs with Cell and 16, where 16 was only removed after his grip lightened up because of the surprise that his self destruct failed. So for me, Piccolo holding him down, ESPECIALLY considering he didn't actually succeed in holding him down all that well, (Cell Max could still fly, move his wings, swing Piccolo's body back and forth, etc.), doesn't actually imply he's relative. It should also be noted that Cell Max was clearly pushing it's body to the limit by creating the power sphere it DID, so regardless, Piccolo doesn't scale. At least, not well, or any significant downscaling outside of "brutally beaten down by the Android, hurt it never."
Also, none of this actually resolves the issue I brought up. Piccolo can sense God Ki. He sensed Gogeta's power. Hell, it sensed Gogeta's LATENT POWER before he even transformed. Piccolo KNOWS how strong Gogeta is. He KNOWS how strong Moro Arc Goku and Vegeta are. And yet, according to him, the Gammas are = to both Goku and Vegeta, and Goku and Vegeta might not have been able to beat Cell Max. No matter how you slice it, we're given explicit reference on where these character sit in reference to Goku and Vegeta in and out of film, and that list goes:
Gamma = Goku and Vegeta Level, likely meant SSB Moro Goku and Vegeta.
Ultimate Piccolo/Gohan ~ Gammas
Orange Piccolo >>> Gammas, can no sell dozens of strikes and lay them out in one shot
Cell Max ~ "Broly," considered stronger if completed, realistically scales above him regardless, his battle on Earth is considered "the strongest battle," this occurs after BlacK Frieza, UE, TUI, etc., told to us by Piccolo to be a threat even Goku and Vegeta would've not been enough for, despite knowing the strength of SSB Gogeta.
Gohan Beast >> Cell Max, with Cell Max potentially nerfed to a mild degree, but his battle is considered the strongest battle, and casually took blows from Cell Max as well as ended a power ball condensed with likely all of Cell Max's power into one large sphere, similar to Teen Gohan, which we know can circumvent loss in power via injury, with Cell Max clearly was pushing his body and power to the limit to attempt to kill Gohan.
Gohan's sadistic weakness is basically gone, anyway, though? There's a vast difference between tanking an attack, doing a punch, and then going for the kill to "let me slowly torture you, call you a '******,' tell everyone no when they suggest to kill the bad guy already because I've not finished having my fun, and in the end allow people I care about to ultimately die due to my arrogance." He took a punch, and gave one, and then killed. That was basically it.