Robot had a mix squadron of both the basic and Volcanic armors around the atmosphere. He made his new suits to purposely stand a chance against a Viltrumite, his old models would be easily rolled
I'm not talking about the old models, the old models very clearly do not scale, and we're shown that. His new models do though to an extent, given we quite literally are told they can harm them, and not just through the sound stuff, and Robot's one he used against Thragg could even do so to the point of mutilation. Eve also goes on record and states that his drones
can and will harm them if they get caught.
That's not only a explicit demonstration, but also confirmation. A chunk of his drones explicitly scale to the hybrids.
In fact the scene works against the point of them having weaponary that can harm a Viltrumite since Mark only notes their sonic armor rather than any deadly weapon.
Sorry dude but disagree.
He's talking about their basic armored drones, and he's saying that because it's an innate quality of the drones. In that, you punch hard, they hurt back via sound. He's warning them of that, but that doesn't mean that's the only thing they can do and the only thing to take into account, just that it's the most obvious thing as they need to fight back in such a way as to not accidentally kill themselves instantly, plus, Eve a few pages prior straight up says they are fully capable of hurting them, do we really need Mark repeating the same thing again a page or two later? It was noted, just not by Mark (And Eve would know how strong they are, given she fought hundreds).
As before if we want to keep the Titanium suit as At least High 6-C that's fine imo, but it's not High 6-A. Mark one shot an armor when he didn't need to worry about sound and Thragg was weakened through constant plasma degradation of his smart atoms when Robot's advanced armor went to Mark.
Thragg and Mark were in the sun for a short awhile when Robot's suit came, I wouldn't be so sure the heat was truly really starting to effect them yet, but even if it did, which is fair to assume, that has zero effect on Robot outside of the sun, and Mark in it, both thinking, if not outright confirming that yes, Robot's high-end suit has weapons, plural, not just one, that scale to him, so it isn't just sonic based weaponry that can harm Thragg, no matter how miniscule that may be.
It's extremely straightforward, to the point there shouldn't even be anything to argue, it's basically just exposition saying "Robot could harm Thragg to an extent with his high end suits' weapons", that's it. And I can almost guarantee that them being in the sun, smart atoms and more wasn't considered there in context, because Mark
doesn't know about that, why would Mark say that in reference to "Thragg is weakened, so his weapons can harm Thragg now", that's not what was said, Mark simply says there's weapons that could, and given Mark wouldn't know about the heat weakness, it obviously wasnt in reference to their current state, he was just saying what he knew and wish he could use and smart atoms is a literal nonfactor because Mark doesn't know about that weakness.
Plus, you pointed it out yourself, the sound based weapons are a literal nonfactor in space, as Mark did that at the end when he kak'd him, so Mark can't be referencing the sound based stuff in the first place in that scene.
Put simply, it's just a straightforward statement that puts Robot's AP near Thragg's dura, even if Robot's dura is considerably less (would still be above hybrid tier though as he can physically fold with his best suits).
tldr but still kinda long.
Meaning, hard disagree, Mark and Robot both think the high end suit has weapons, plural, that can at least harm Thragg, it's not talking about the sonic vibrations given 1. That's an innate quality, Mark wouldn't "need to know" how to work the suit to utilize it. 2. It's plural, even if it's talking about the sonic stuff, there's at least one other thing as well. 3. There was an entire fight between Robot and Thragg offscreen, we can easily assume that the weapons in question were used then, and Mark seen them (given he was right there), of course Robot lost that fight and his armor was torn apart, but there was a cut, and there was a fight of some degree offscreen, Mark would know if it's packing some extra heavy duty weapons even if we don't. 4. The fight took place in space and in the sun, the sound based weapons are useless, Mark can't be talking about those there.
Honestly, at the end of the day, there's nothing to argue about, we're told Robot could harm Thragg, even if only a bit, and it's backed by that same suit's (weaker) innards folding hybrids physically to the point of brutalization and mutilation and him having zero issue with them, and multiple at once even given the suit was fine when it needed to go to Mark (on the same page where the shit brickhouse that is Allen is having a bit of issue with just a handful at once), and it explicitly said weapons so it's not the built-in defensive option which quite literally couldn't be a factor in that statement given it was in space were sound is a nonissue nor would it be the sound based weapon for the same reason plus, as Mark states there's multiple weapons that can, not just one.
Though note, I'm not saying this is for every drones, suit and so on, just his final most powerful suit used against Thragg, as that's the suit it's referring to and the only suit that was shown of that caliber, and that's only for AP too, not even durability. The rest can be lower, that's fine given their feats.
Also sorry if I repeated some stuff, I'm super tired so it's not a super cohesive reply.