As new classes continue to come out that variety of gear dropped in coil will increase yet the chances of getting a particular set of gear will decrease further especially in regards to armor pieces aka equipment worn on the left side of the character window. Once ninja comes out there will seven unique armor sets that can be worn by particular classes (tank, healer, bard, dragoon, monk, ninja, caster). So getting that particular armor piece that you want for bis will be even more difficult unless you're lucky. I completely understand why ninja has a different set of armor pieces so that the class retains its unique feel and isn't a monk lookalike with daggers.