I really enjoy this game a lot, but there are a few things that would make it much better.
1) There really needs to be an option to set your units to automatically attack enemies when hit with ranged attacks. While fighting on multiple fronts its really easy to miss a ranged unit approaching and it can easily decimate entire armies because units just sit there. Adding this would make battles much better.
2) There should be an option to set units to automatically attack units in an area, not just when its been attacked. These two ideas are basically defensive and aggressive formations like in most RTS games, adding them would be a great idea.
3) There should be an option to tell your soldiers to use an attack move - telling them to attack all enemy units on the way to a location. This makes it easier to control battles on multiple fronts.
4) There should be an option to set an order to repeat. For example, If I have a sqaud of slaves I want to walk from Pellas all the way to Molossis delivering food over and over, it would be much easier if I could just hit a button for peasants and slaves to repeat the command rather than constantly doing it myself. This is a great additition to the supply arrangement as it is very easy for things to get bottlenecked in some areas.
5) Finally it would be great to add a patrol move to soldiers. This way you could tell them to patrol along borders, a very consistant activity of militaries throughout time. Adding this would in essance simply be an attack move repeated between two points over and over again. If you include the option to repeat an order, then you could set slaves/peasants to supply them with food periodically as well making a very effective addition to managing borders and wars.
These five ideas really just open major tactical options and allow the wars to be more easily managed. These are very common in most RTS games, so it will be very good at drawing and maintaining those gamers. I myself love this game, but the lack of these features does push me away a little bit. Finally since none of these things would be mandatory in game -even the aggressive and defensive stances in 1) and 2) would be supplemants to the standard stand ground behavior of troops in game- those who would prefer not to use them can choose not to. By adding these though, the player feels much more like a king of a country with more tactical options.