With our new found joy of /click
Was thinking about some of the large draw backs people were mentioning, one specifically is the pain when adding or changing characters from the group and needing to manually change every macro as the targets are hard coded.
This would also allow for a much easier configuration when changing spells.

For starters I am using macaroon, I created 3 bars
Bar 1 has 5 buttons (one for each character) and the buttons are ActionID1 -5 with macro's in each with simply /assist CharName
I have another bar with 12 buttons, 1 through = bound to them and actionid6-17
The last bar has my hidden buttons with binds to correspond to the second bar.

Each hidden button will have the corresponding code with the /cast actionid to match it's active button.
Code:
/click [mod:CTRL,nomod:ALT,nomod:SHIFT] ActionButton1
/click [nomod:CTRL,mod:ALT,nomod:SHIFT] ActionButton2
/click [mod:CTRL,mod:ALT,nomod:SHIFT] ActionButton3
/click [nomod:CTRL,nomod:ALT,mod:SHIFT] ActionButton4
/click [mod:CTRL,nomod:AlT,mod:SHIFT] ActionButton5
/click ActionButton6
/targetlasttarget
This allows me to do a couple things. First I can drag and drop my assist macro's from my standard macro window to the first bar if I ever change my group, and second I can change my cast spells cast just by dragging the spell (or macro) to the appropriate spot on bar 2.

(Forgive my for the horrid and confusing right up, I am not a technical writer.)