Warriors will just have enough SkS to squeeze 5 FCs in IR window, not more.
Arrow wouldn't change that, no way you can get 6 FCs in IR window without losing too much on other stats.

DRK might profit from it, even 1 more GCD in Blood weapon window gives additional mana, thus damage and/or mitigation through TBN.
The benefit is still minimal and arrow is better used on a DPS role.

Tho, all jobs will try to arrange thier GCD to fit with thier buffs. Arrow will throw off thier rotation in most cases.

No job really takes an arrow into account, getting it is too rng.