Predict some Magician changes.

All 3 warriors have rush skill, does it make it a single class?
Buff skills like SE, haste, etc are not unique to a single job so why can't HS. Remember CBs did not have Shadow Partner/Flash Jump.
All 3 mages have their own unique playing styles anyway.

Mages have in common (some are thematic skills which I'm also considering here since it makes each job less creative):
2nd job: mp eater, mastery and teleport
3rd job: teleport mastery, some resistance
4th job: big bang, mana reflection, infinity, summons, ultimate and buff mastery (not counting the similar one-side mob skill which plays the role of 1v1).

And there's not more simply because Bishop is a little more unique compared to the other 2. Their playstyles for 4th job are way too similar with that many similar skills.
It's the only class that instead of diverging in 4th job, converges.

Compare that to warriors, each has a different mechanic to them and skills that work very differently.
BM/MM are quite different as well starting from 4th job.
Not even gonna say anything about the thieves or pirates.