Concise description:
It doesn't make sense losing armies to your doubles partner. In a real battle the ally would give his territory to his/her partner. For example, in a recent game I had 10 armies in a territory and planned with my partner to take his 1 in another territory so that I could get the bonus. I lost 5 armies trying to take his 1. He should be able to just give me that territory. Completely changed our strategy because I didn't have enough to guard the land and we lost our bonus.
This will improve the following aspects of the site:
Doubles is a partners game and if your partner agrees to give you a territory, then you shouldn't lose armies taking it. I would suggest any territory that has 1 army, the partner should be able to take it without losing any armies. I say 1 because this would eliminate any abuse where a disgruntled player decides to wipe out his partner. Or maybe have a button that allows the partner to confirm and forfeit territory...something in those lines. This would make it easier to strategize in a doubles game.