General question about expertise in PvP

Hi everyone,


I've seen quite a few very decent (skill-wise) prot warriors gem for expertise aiming for even 30 expertise. I have a BIS prot warrior and I think I have a very min-maxed build that I spent a lot of time on, and I can't help but notice the huge loss of seemingly more important stats as str which converts to block value+AP and crit (given we keep 100% arp, no matter what) SBV I see some people keep at 1975 (including me) and some people keep between 2k and 2.2k

Can someone let me know if there are things I don't know or what stat is worth compromising for the sake of gaining more expertise?

Thank you!

Correct me if I'm mistaken but I assume that special abilities like shockwave, Shield Bash, Shield slam or concussion blow can be parried or dodged.
The general argument against expertice in PvP is that players aren't able to dodge and parry attacks from behind, but in reality you won't be able to always stay behind your target. Especially not when you fight other melee.
I have also seen high rated Awarr using https://wotlk.cavernoftime.com/item=50678 or https://wotlk.cavernoftime.com/item=50728. I'm just guessing here but I believe that they wanna make sure that MS doesn't get parried/dodged so they don't lose the debuff on the target.

I assume it's probably worth to switch ring and neck to expertice against certain matchups.