I don't think their hide is the issue, and I wouldn't call it enhanced since in some ways it is weaker than thief hide.

Also wasn't Sertius the character an assassin? I don't remember you noting it was op then.

Imho the problem with assassins is the change that makes some weapons easier to dodge if they are hard to parry (in effect). It means weapons that used to scare assassins now don't, and that's even before you consider martial trance.

I remember pulling off a perfect pk against a charged blood lusting fire axe wielding ap before the changes (Kans, kot then dropping both weapons, throw to seal the win). Now such an ap isn't really as dangerous because you can defend well against all of their weapons, and wouldn't be a memorable pk. But also it means an app is less likely to bash you without protections and more likely to wand up if he's the aggressor, and that is more boring.