You need a target for auto-shot, wanding, channeling, and auto-attack. I don't want to sound like I never use /assist. I do. I just don't use it as my only way to target mobs. I use it at the start and then 90% of my spells use [target=focus-target] so they go off on who I tell it to, not whoever they want to. It might sound redundant, but to me, /assist is for auto-something mostly. If someone (my tank for instance) auto attacks someone else, no biggie, if his sunder goes off on a random mob, that kinda stinks. If my locks accidentally melee a mob they aren't supposed to, I don't really care, but if they put a DOT on a mob they weren't supposed to, that makes things worse. If my hunters auto-shot a mob for a few seconds, my tenacity thunderstomping bears don't mind, but if they continually put a arcane shot up a mobs butt that they aren't supposed to, it makes things worse. So you can /assist all you want, I just try to teach/help that having a designated target for bigger spells/actions. Just my 2cents.