Have it so orcs get an extra attack turn. Humans and dwarves can have an extra gold income. Elves can have 2 extra sab turns per guy, or make it per every 4 turns, so they can use 4 sab turns 3 times. Undead can have an extra attack turn and/or extra unit production. You can make the extra attack turn and an extra gold income every 2,4,6,7, or 12 hours or something similar. With classes being even more different you can have a certain play style easier. You'd have more advantages/disadvantages against other players and it would determines people skill level better.