Why no focus? FOCUS IS FOR SHEEPS YOU NOOB!
On main character (party leader): Bind the key to "Mark Star raid target"
On mage 1 character, bind the key to the /assist macro above followed with a /focus.

Repeat for each peice of cc you want to do.

Next bind one key on all characters to perform their cc on their focus
/cast [target=focus, nodead]; [target=target, nodead] CCSPELLNAME
Just curious about saving focus for sheep targets. I set my main as focus, and use target=focustarget in my dps spells. I find this means less incidence of waiting for the /assist to catch up to the main's target and accidentally DPS'sing the wrong target. This also means I can manually assign targets on my alts, or use /assist to get all the alts targeted on one particular mob.

Are there scenarios where this would be a disadvantage to using /assist with /focus for CC?

Cheers,
Stealthy