If you look at all the other bp's that drop off of the Avatar's, yes they all have +40 critical mitigation, however Wu's Enlightened Chestwraps is the only bp that has +150 combat art damage, the other ones have +10 to +15 to combat art damage. I would guess that the critical mitigation is lower on the Wu's because of the off set to combat art damage. So it might not be broken from that point of view, but more of a give and take (or balance if you like) situation.
Any thoughts on this?