I had to deal with this as well as a fresh 80 Shaman Boxer.
[AV has to be the best place for me on any of my teams,but since its empty I do EoTS also].

I found that most players do round after round of BG matches and get into a routine.
When a Multiboxer comes into the match they just can't adapt fast enough or at all,to the shifting team dynamic.

So there are 2 methods I use,one is the same as Oatboat posted Capping the Towers fast in a square route or holding back and switch capping 2 towers facing each other and guarding the flag runner.
Anything else seems to complicated,in fact i'm positive many players don't even toggle their maps.
[Any yes once the opposing players realise you are MB they will hunt you down and farm you].

Hopefully AV comes back to life soon and I dont have to do EoTS AB WG or Spam of the Ancients again.
Hope this adds to the pot and helps.
GL