In what way do H4 battles have more ways to be resolved then in the other games?
I am not sure what you mean, so I will just discuss it a bit with myself
Outcomes of battles - win, loose, retreat, surrender or both loose.
There are different ways of doing those things in H IV, than i Heroes III for example, but I cant really see more possible outcomes. Ok, there is actually one more - your potential enemies join you. But that is also not a new thing. (Actually corret me if I am mistaken, I dont think you can avoid the battle totally in heroes IV, since the whole stack never joins you). And in principle it would also count as "win".
I is of course possible to avoid a battle in HIV by sneaking by you enemy with stealth skill, but I would not count it as "battle being resolved"
So I guess my answer to your question would be big fat 0. But I know I am missing something here.