I'll point out that The Arrow isn't all that glorious as it seems to be on black mage. While they can empty their MP quicker while in astral fire, they're still gated by the MP recovery intervals during Umbral Ice. If anything Summoners and Red Mages would be a better target for more consistent result. Summoners only when they have their bahamut out or you know it'll be out soon.

For job specifics:
Monks can do a double bootshine rotation with the added speed
Ninja are sort of the same as Monk in this sense
Dragoons tend to get confused as their rotation is significantly more precise compared to other melees
No idea about Samurai yet, need to do some proper testing and questioning with an "expert"

And against all logic; tanks tend to be pretty good targets for The Arrow if they are the kind of players who don't tank in their appropriate tank stances. If enmity is an issue, the added speed from The Arrow allows them to stay out of tank stance longer or the DPS don't have to hold back