There is actually a very good reason for the three different melee sets if you think about it. Allow me to explain.

Ninja cannot share with the other two, different main stat and SE don't like adding main stats that aren't used, they have only done it when patching dex on to monk gear so they didn't have to create new sets of pre 2.3 gear. That's one melee removed.

Monk and dragoon cannot share the same gear because Dragoons are a heavier armoured job made to wear gear with a higher physical armour rating. This is evident by the statistics of every piece of dragoon gear compared to the other melee job pieces. This separates monk from dragoon.


You may not like these reasons, I personally can't see why str and dex on one piece would hurt the game, but they are valid reasons. Hope this helps.