how about the following

Code:
/target [nomodifier] char1 [modifier:shift] char2 [modifier:ctrl] char3 [modifer:alt] char4
/focus target
this way you can easily shift focus to any of your characters. I don't have a char5 on there cos if he is the last one left then there is no one to assist him!

I have separate keys for
Code:
/assist focus
and don't include it in my attack macros