IMO in a BG setting only (non-arena)

You can go wrong stacking classes.....Hunters,warlocks and shamans. They all excel in BGs.

Hell I would imagine any 5 man team might just do fine in just BGs/world pvp.

I have Quad shamans, 3x Hunter and a 3x warlock team and well BGs are just easy street. I just choose which ever one I want to play that evening.Now with pet scaling hunter,locks will be even more powerful.