If 4+ Mobs you should spam scatter and then moulinet when appropriate.

At 3 mobs hit the rdm sweet spot. Scatter then instant aero/thunder to build mana gauge. Alternate between all 3 targets with your single target attack.

Why not use diversion? Well, usually Lucid Dreaming is enough. Our Aoe isn't that great. Diversion I carry most of the time, but find it a little unneeded in aoe pulls, since I'm going to pop lucid anyways. 100% Need it for bosses though if you give rdms a countdown lol