I've yet to try out Castle Wars, I'm afraid, but I do like the sound of this idea.
Let's see...Since this is Vvardenfell, Hlaalu, Redoran and Telvanni should be the only Great Houses involved.
Redoran should have few and expensive warriors, but they would be be stronger and better equipped than the warriors of the other houses. Like their doctrines state, they should primarily wield longswords and spears. They could be backed up by temple priests and a few scouts with ranged weapons.
Hlaalu wouldn't rely on brute strength, but would instead use their wealth to hire mercenaries and the like, and use their own stealth and guile to back them up. In a realistic setting, Hlaalu would probably use political manoeuvres to win rather than military ones, but that's not what this mod is about.
Telvanni, like Hlaalu, would primarily rely on mercenaries, but with less wealth, they wouldn't be able to hire as many. They would, however, be able to provide them with enchanted items and other magical trinkets, as well as provide backup with their powerful spellcasters.
That's my opinion, anyway.