I'm not sure yet, as I haven't detailed out the campaign I'm preparing yet. But I'm thinking both really... If need be, I can do with the very most basic, but I'd love to have everything at my fingertips if possible.
skip williams is writing a book for malhavoc press on including a war in your campaign... but it woun't be out for a while... i'm pretty sure it has some mass combat rules in it.