I imagine the RNG is there to make the rotations more dynamic (rather than set in stone "this is wut u do mang"), although it seems like it would be much harder to balance jobs based on RNG in certain scripted scenarios than those not (especially in the eyes of players, cause most of us suck at math.. me thinks lol ). We'll have to wait and see I think.

Definitely looks like they have lesser AoE damage, but I'm thinking their ST has been improved a bit with the whole Bahamut Ahk Morn and attacking on top of all your spells things.