This game needs a Play By E Mail mode and needs it BAD. I am stating that because the PBEM system is what made Age of Wonders Shadow Magic so successful (I used to be a very active member of the AOWSM forum, where the the developers used to come and interact with the members). The only thing that makes AOWSM a little more right for PBEM is that characters in AOWSM have a little more movement so that one is almost sure that every turn something happens. Also that makes AOWSM games last about 100-150 turns at the most which means that when people play one turn each day games would be over in a few months. Once I played a game that lasted over a year, but that was just once.
With EWOM every large game would last 3 years and many turns would see the players just doing nothing. So that's my input: Try to make a PBEM mode, test it and if most turns get boring, just see what happens if units go let's say twice as fast... But of course nobody would force players to play on large maps, so maybe testing this mode would just prove that it works as it is.
The whole AOW community has been waiting for AOWIII since 2003, they re still there (go check the forum: AOW Heaven) they are MANY and they would love to become your costumers.