No, MegriM stated a lot of times that he doesn't test balance with PvP fights, only through war (look for posts by MegriM with RvR and PvP as keywords
).
Knights seem hard to kill because they're not "insta killed" by your barb like all classes, but this is needed. Barbs should be able to go cast Brain Piercing to a rushing Barb, the problem is that 3 Barbs rush at once, you cancel one area then 2 are coming and gonna kill you because they hit so hard (often 1500 even to Barbs!).
As for Army of One it is good only if you have precise block lv 5 too, or else it gets wasted by all the -health modifiers (or Throat cutter ;p). That's why I hate it as it is, 500 mana for AoO + 450 for deflecting barrier (protecting other warriors -- including you
) and you are left mana less. You need to keep some for Precise block every 30s and so you can't cast damaging skills, and obviously can't cast an area (since you can't have Shields 19 + Vanguard 19 + an area, since every knight *needs* tactics).
Then there's mindsquasher too
. Now if you see the edit of my previous post, you see that a knight will have to sacrifice attack for such a passive anyway.