I'm in the process of coming up with army lists. If you have one for any faction, submit it.
I'm currently working on how I am going to set up a recruitment system for the factions.
Extremely rough idea for Byzantines:
1. Tagmata: These are the troops of the central army. They are only recruitable in Constantinople.
Ex.:
Domestikas ton Scholon
Excubitores
2. Themata: These are the regional troops. Not all troops are available in all provinces. The core units are available in most provinces, and 'local' troops in other provinces
Ex:
Peltastai
Akontistai
Cavalarii
3. Mercenaries: These are recruitable foreign troops. They will mostly be the same units you would find as mercenaries in certain areas.
Ex:
Skythicon
Rus Warriors
Armenians
That's just a brief idea of where I'm headed. Not every faction works the same way.