Hunter's need mobility, Warlocks need resilience for their main ability recharge, Titans need resilience which coincidentally is the best overall armor stat in the game. I don't think I need to tell you why having a better ability to absorb damage is great. To me, if you're trying to make it fair, have Titan ability recharge to strength, which also plays into the class fantasy. Yes it would suck to regrind armor and Bungie would probably be better off redoing the whole armor system in order to make us ALL regrind some armor.