How would you feel if Warlord's wasn't a Crit mastery at all?
As in something like 'Dealing more than 10% of the target's max HP in a single attack heals you for 15% of the damage done and grants you 20% attack speed and 20 ability power for 4 seconds.'
It seems kind of silly that the sustain capstone is only available to crit-builders.
I don't think fervor is comletely useless on caster-y birdfolks