Hektor kills Herc 1 time with an A-Rank Np while a Buffed Caliburn can kill Herc 7 times over, As Rank A+. That's a comparison of power isn't it? Is that a 6x difference?
I have the scans if needed. not idea if this is usable though for anything though..
Again I don't believe he killed him with the spear throw, his life was lost because of Chaldea killing him once, then the Hector thing happens after, and Asterios just cast both of them into the ocean so that Chaldea can escape, I don't remember Herc ever dying to it there.
Nuh uh, that's not how it works, the burden of proof is on you to prove that A Rank NP's are comparable to A+ Rank NP's, the higher Rank means a lot as A++ are far stronger than A+ NP's
Higher Rank = More Power
So you need to provide evidence as to why A Rank is the same level of power as A+ Rank
Incorrect, it'd be on you because I'm not the one making the claim, you're making the claim that they are absurdly strong in comparison, and that's what needs to be proven. As shown earlier and recently by a few others, higher rank doesn't equate to huge power differences always, for any rank differences, let alone one in the same letter grade.
Bellerophon is 2.8 teratons, so Saber Alter basically took 280 gigatons of AP and was severely injured from it. That's consistent with 6-C base Servants, and way more consistent than taking a full A+ Rank twice. Sure, it happened twice, but it's inconsistent with other feats of NPs nuking or severely wounding Servants, and even the established fact that NPs are basically special moves that are far above what a Servant can normally do.
Its not really inconsistent with them dying to NPs. All of your examples thus far besides the Saber being wounded one, have relied on Herc, who, as I said above, has an absurdly inconsistent defense, so you can't exactly use it to say other things are inconsistent because he dies to it and Nero doesn't die to something. The Saber example is closer to proving its an inconsistency, but she did in fact survive it after the clash (the light isn't exactly all the power of the NP anyway, it's the literal Pegasus charging you that does a good bit of the damage, so even offsetting the light doesn't make it super weak but meh), which further shows that Herc dying 7 times to an internal attack doesn't exactly make for the best benchmark of things.
So you have Nero surviving Galatine twice, making it consistent with itself.
Vs Herc's inconsistent defense, that doesn't protect his insides, not protecting him from Caliburn, and, more reasonably, Saber being wounded by Bellerophon after the clash, in which the Pegasus still smacks into her.
So even being generous, that's 2 super early examples going against 2 more recent examples, and as said above, the more recent ones are typically used anyway, and it's only 2 against it if we use Herc as a benchmark for whats consistent even with his inconsistent showings, and ignore the fact his insides aren't protected.
So no, that doesn't really prove the Nero thing is inconsistent.