To touch just upon the Grail Knight at this point, I’m afraid the fundamental problem lies within the fact that he is a Grail Knight. These guys are completely over the top and beyond ridiculous in Warhammer lore. They eat armies, malevolent champions and great monsters for breakfast. Someone who has proven himself worthy before the Green Knight and the Lady would simply have no issue walking over anything and everything that Vermintide II currently throws at the heroes, which is low-level to mid-tier enemies at best. A handful of Grail Knights can, according to Warhammer lore, get as much killing done between themselves as an entire army of ordinary soldiers. So this career should completely blow Merc & Foot Knight out of the water in the melee combat department, given what it is.
Of course that you need some measure of reason for the sake of gameplay, but making it an objective to bring him in line with Kruber’s other paths conflicts fundamentally with his identity as a Grail Knight. He could have been a Questing Knight perhaps, but the decision can’t be changed at this point. That being said, in my opinion he isn’t a major offender currently. Powerful for sure, but I think he requires plenty of skill in order to actually perform well. I see plenty of people struggling a lot with him in public games, generally due to the lack of understanding of basic game principles which become quite relevant when you don’t have a ranged weapon or damage mitigation. He could use more meaningful and interesting talents, but I don’t think his killing power is out of line with what he is supposed to be. I don’t really play mace&sword or executioner sword so I can’t comment on their performance from my own experience, but when I see people running them, they are either doing great because they are fantastic players with thousands of hours of try-harding on board, or they completely pancake to slave rats because they don’t have a clue. It’s hard to judge these things in a vacuum.