Where should I invest my Attribute Points in MCH?

[Ryaz]

If you're DPS or healer, you should always put your stats in what the class uses the most. For NIN/BRD/MCH, it will always be DEX. If it's MNK/DRG, it will always be STR. If it's SMN/BLM, it will always be INT. If it's SCH/WHM/AST, it will always be MND. Tanks get a bit of leeway on theirs due to both STR and VIT being good, so it's down to preference for them. For everybody else, you go all in.

Monks don't use Dex? I remember them sharing gear with ninja.