PLD has Sentinel, Sheltron, Bulwark and Passage of Arms. Bulwark and PoA can't be combined with Sheltron as all block damage. Bulwark is ok for dungeon pulls but has a long CD. it's crap for single target/raids. How is that solid without cross class?

Also Sizzle, if you want balance you should care as much about the other tanks as you do about DRK.