I think there may be a misunderstanding here, the tokens don't just represent armed forces, they're an abstraction of the factions resources from soldiers to morale to propaganda.

Considering the original plan was to resolve things in the "least-asshole-ish way possible" I'm pitching this as a way to keep things fair and semi-strategic without getting anyone bogged down in keeping track of individual units or stats.

Anyway I'm not saying your idea is bad or anything -- I'd be happy to use it if everyone else wants to -- I just don't think that amount of detail is necessary for this particular thread.

EDIT: Sorry but I'm not sure that your surplus suggestion is in the spirit of the thing.  The point is that you're gambling your resources while trying to guess how many your opponents will use, in order to use up as little resources as possible.  If you allow the surplus rule than the risk/reward nature of the bet goes out the window.