You can't just ignore how the classes are balanced in regards to armor balance. As stated above the titans may get an exotic chest that gives them the same perk a warlock can have simply for being a warlock. If anything the different gear makes it so a titan/warlock/hunter are more homogeneous in their lack of clear pros/cons. If a titan needs to equip a certain piece of exotic armor to have an extra grenade, there is an drawback due to the fact that A: one exotic slot is used to give the same perk a warlock can just use a class ability for B: precludes the use of another exotic with different perks