Priest/Cleric and Troub are the only Base Classes with Staves. They can't attack, but Staves are... staves.
Staff Access is pretty big.
That's what we have Lissa, Maribelle, and Brady for. MU may as well be attacking.
Worst promoted is Griffon Rider. Underpowered, even with Axefaire and a +Str modifier.
Trickster at least benefits a +Mag MU with Swordfaire.
The catch is that Staves are always solid.
Thief literally does nothing but be awful. Terrible offense, it's utility is summed up by a skill, and even that isn't that great since there's like 1 important chest in the entire game. There's more KEYS than chests that you need to worry about. Thief is useless.
Having another Staff user > Having a pointless attacker doing terrible damage who READILY could be in a much better class. And Swordlock is the worst of the weapons to have a lock to. BY FAR.
Both are terrible, bad options for MaMU, but of them, Thief is ever so slightly worse.
Staff utility is also what puts Trickster over Griffon. Terrible choices all around, but Trickster edges Griffon with Staves over flying. --- Now we are here we know it's too late! Today we hope to find some closure! Silently waiting, do you hear a calling? Look into the wanting eyes, I'm still here!