The actual values this tier is closer to Weapon Damage > Agi > Hit >= EXP > Crit >> Mastery >> Haste
Crit is much higher value than mastery due to pet's being so starved for focus. Until you can get enough Crit to comfortably sustain your pet's focus to be able to use his pet attack every 3 seconds, then you're losing out on a lot of damage.
Once you get to that point, Crit/Mastery become relatively equal, but it won't happen this tier. I am nearly full BiS and my crit levels are still way to low.