I doubt that I'm stating anything new, but just in case.....
Pathfinding during combat. I usually send out a horde of ogres, which works fairly well for most fights, but theres always one or two, sometimes more, that dont fight. They just stand there doing nothing, while their buddies are getting swarmed. There probably are those players who like the micromanagement style of clicking on each individual unit in a fight and controlling it, but I'm not one and I'd bet most people dont want to individualy have to get each toon to get into the fight.
Dragons. They dont really do their firewall where you click on it to happen. Somethimes they do, most often not. They also seem to just stop fighting occasionally and stand there getting beat on. Even if you have them set to 'aggressive stance'. They also seem a bit squishy. Some of this is offset by their hit points and regen, but they still take a heck of a beating, even in
comparison to the aforementioned ogres.
I'd like to see the building options continue in the towns. Especially further fortifications, at an exponentially increasing cost, both in time and resources. Maybe the ability to purchase and place individual towers.