Very good idea, multiplayer will be really big game improoving but also big step for popularisation this brand. If I understand correct, autor want to see PVP like arena where both players have similar starting army and eqipment.
Reasonable idea create a separate field without global map. Will be enough citadel screen with all buildings, tavern with 30+ peoples and some starting money for normal eqip (10-30-50K gold). And joining throw arena to other player. Also recruit’s settings could be changable from 1 lvl to 11 lvl with eqivalent money options.
I think multiplayer in this tactical game will be very interesting for old players and for new gamer too.
You have good AI, but PvP game always more interesting then PvE.
Thanks in advance!