I feel OP's being too conservative with his CDs. If you're MTing as WAR for OS3, you should feel alright using holmgang whenever you can, and awarness+another cooldown. Heck, you've even got the choice to switch to defiance for those critical hit tank busters to supplement with inner beast. Given those tank busters occur 7 times in a fight, there's nothing wrong switching to defiance just for those situations to inner beast, especially in between zerk windows.

That said, you can totally use CDs outside of tank busters when there's a lot of outgoing damage when MTing in deliverance.