This is a very simple addons for AV(/WSG/EOTS/AB/SOTA) Groups.
You save your raid with a macro:
/script AVRaidSave() - Also bindable to a key through the ingame keybindings menu
Now it scans the raid and saves who is in which group If you are in the BG and are the Raidleader, use macro with:
/script AVRaidRestore() - Also bindable to a key through the ingame keybindings menu
It now exchanges people in the raid, trying to accomplish the previous raidsetup, but will most certainly not go perfect on the first time. Just wait one second, hit the macro again, until nothing is changed in the raidroster.