The following is my observations from 2 weeks worth of anima weapon grinding via DF with some hunts thrown in.

Warriors seem to be the dominant tank from what i have seen, with a great number of them being deliverance driven block-heads hellbent on making a healers life hell. Paladins and dark knights still somewhat common but greatly overshadowed by the block-heads.

For melee, i think dragoon might be the most common but i feel like i see ninjas just as much. Monks fairly rare though.

Ranged seem to be a plague upon the DPS queues, having just finished the relic grind via DF spam i can easily say that both bard and machinist seem to fill almost all DPS slots followed closely by...

Summoners are also incredibly common as of late. Black mages seem to be increasingly rare as well.

Healers all seem about equal with scholars possibly lagging behind a bit, but not enough to worry over.

Most common overall would easily be the fell cleaving block-heads.