FCoB does have mostly physical attacks. But parrying 4 more attacks per battle or 8 more with a 400 range parry attack is not going to save you. There is also a lot of tank swapping and dead time. The problem with parry is the number of extra hits you will parry per turn. I'll check my t11 parse if I still have it for how many hits I actually take in a clear. Its a very small number and I stand in front the entire time.

My point is if you only take 100 hits in 10 minutes and you parry is 15% or 25% that is only a difference of 7 attacks total with most of those being just AAs.