I use this to set focus:

/focus [target=Bugged, exists, help, nodead];[target=Shamin, exists, help, nodead];[target=Sheamen, exists, help, nodead];[target=Shaemen, exists, help, nodead]
/follow focus


Bugged being my pally then my shammy's. Then on all my toons dmg spells I have them target focus the /assist focus.

I also have another macro so all but the pally focus's on a shammy and they all assist of that one.