Suggestions for Mass Combat…?

[FireHorse]

I have a scenario / adventure in which the players would be part of a much larger battle. While the players would resolve their own combats normally, obviously it would be wildly impractical to use normal methods to determine the outcome of every individual melee within that larger battle.

However, I do want the outcome of the players' fights to affect the overall outcome — they're the Heroes, after all, and they'd be facing off against the Leaders (and high-ranking sub-Leaders) of the opposing faction, and Morale can sway the tide of battle. (If you kill a group's Leader, for example, it should make their followers more likely to break.)

So I'm looking for two different things:

1. A method for deciding the outcome of many separate fights, without having to roll each one individually; and…
2. A method of applying Morale (resulting from the outcome of the players' individual fights) to the outcome of the larger battle as a whole.

Any suggestions…?