I am not really using an assist macro, I just put assist focus in every attack macro that needs it like LB, CL, shocks etc.
I can switch focus when my leader dies and let the rest follow the new leader, that is not the problem.
Only when I am cc'd I cant get my alts to attack a different target causing me to do nothing for 6 seconds.
I think my lightning bolt macro is correct and assists the focus target, if not enlighten me please :P

so for example:
1. My team is nuking XXX target
2. My leader gets hexed
3. my alts continue to attack the shadowhunter till its dead
4. when the shadowhunter is dead, and the leader is still cc'd, my alts are unable to switch to a new nuke target while my main is still hexed.

Thanks for the help!