Test it out with one of your guys if you're interested in the "non-focus" mojo - I use these for my attack macros...

/cast [harm] [target=targettarget, harm] [] Chain Lightning

The only catch is you have to remember - your slaves (the non leaders) have to have the BRAIN targetted at all times. Hasn't been an issue, just something I've had to keep in mind when lookin at my groups targets.

that macro will cast X spell if you don't have a friendly targetted, but will cast the same spell on your friendlies target if you happen to have a friendly targetted.

setup the rest of your slaves offensive spells (or healing for that matter) using that format and you're set!