Hello Krook,
I agree with your summary entirely, the exact same thing happened with my first battle in RTW. I had my HA and my mate had his cohorts. I had no arrows left, his cohorts were exhausted. The stuation, as you described, is a stalemate.
The outcome was a draw, we both agreed on that and it was a fitting end to a hard fought battle. We do not need this as a new result, a draw exists already in campaign battles. In MP all it takes is for an honourable opponent (such as my mate) to declare the outcome and for the other to agree.

Not all battles ended with a clear winner

.....Orda