It looks like they have removed 25-man rated battlegrounds.
But you could certainly run 25-man normal AV's.

You receive experience, at the points where you would receive honor for achieving objectives.
So maximum experience will be achieved by completing the most objectives, along with the win.

If you wanted repeated losses, but maximum losing honor...
Probably ensure you take out Galv/Belinda in each game.
And that you take/hold-until-burnt two towers/bunkers.

AV seems to be a zerg to the end now.
So, three objectives should complete shortly before winning/losing.
If the other team does not actively defend the general, a five box decently geared set of toons can handle the general and two guys up.