Simple put.

NIN uses DRG potency GCDs, with MNK TP Cost, then has GL3 on top.

Basically, NIN is overpowered, no matter how you look at it really.

DRG really needs Heavy Thrusts potency increasing to maybe 20-25%, then it'd be able to equalise the other DPS.

Also 150 magic defense we're missing would be great too.