Ok...

Assuming you want to be good at Arena based pvp.
You'll need an assist method which lets you switch toons quickly.
A variation on the FTL system is pretty much required here.
Nothing else lets you switch to any toon quickly, and control them all, on the fly.

You'll need a pvp oriented talent set up.
Research what others are using and go from there.

You'll need Focus to be free, so you can have one toon sequentially target the other team.
Your other members (and the main toon) have a macro.
Something like:

/assist Main
/Focus
/cleartarget

Now you have focus set on all of your toons, but as far as the opposition knows, none of the followers have targeted anyone. The main has, but he's targeted everyone for a bit.

When the druid (if its your focus) stops pillar humping, and comes into the open for a moment too long, or the priest (if its your focus) casts one too many mass dispels, you hit your destroy my focus hotkey, and obliterate them, despite still targeting their warrior.

Well, cannot really help you a whole lot.

You'll want the Gladius addon, that seems to be the current Proximo.