I just had something dawn on me:
Max block.
Even if you have crazy 40k ar, the difference between that and someone w/ 20k isn't that much when you take into account that 3/4's of hits are going to be blocked.
Sometimes it's just the "randomness" of zeal vs. zeal (you may block 5 hits in a row or something like that).
Technically speaking, 40k ar hits more than 20k. However, to get 40k ar, you basically have to have a shit build like that one lol (no deadly strike, damage, dr...wtf?)
It's all about balancing between your stats