Actually strictly speaking, WAR was the preferred MT in T5. Inner Beast every single tank buster was insane. It's just that people stuck themselves in a hole that actually didn't exist. WAR pre-3.0 is IMO easily the single best MT in the game. 3.0 ahead is kinda hard to judge since WAR is great at both OT/MT with the existence of Deliverance and Fell Cleaves, and also plethora of kits in Defiance.

Note: Did you see how those minimal ilvl challenge (i55 armor + i80 relic IIRC, pretty sure it was followed up with a lower ilvl weapon) by the top groups in T5? WAR MT, yes.