If we as a community push them to make one unplanned change, we take away resource from two. Thus, we must ask ourselves is having them spend the time to redesign and reimplement entire systems to allow for co-op multiplayer or just making the game feel epic worth them being able to redesign tactical combat or the economic model. I think, if we are thinking carefully about it, the answer is no.
I guess it´s not that simple, but in the end the outcome is the same.
I think that getting the basic system straight, fit for MP and SP, better economy and diplomatic system, etc., would be a thing that you would want to do as early and as fast as you can.
So that you later don´t have to worry about it anymore, don´t need to change parts, which would make a rebalance necessary.
Problem is that this would take a while and players would be constantly nagging about the release of new patches.
So, I guess, a compromise is the only practical answer, which leads us to what you´ve written.
As to things that I would love to see (but don´t expect to be) in Fallen Enchantress.
I would definitely like to see more interactivity with the gameworld, especially with terrain.
I want foodoutput and the likes to be determined by the terraintype you build on.
By the way only this could make handling massive armies realistic.
Cause the problem I see with big armies is that they would overshadow single heroes, where in most fantasy fiction the individual hero is the center of the story.
Now realistically seen, heroes couldn´t beat a whole army all on their own, but they have other advantages.
One advantage is that they´re easier to manage and control a lot of firepower in just one or a few units.
This is ridiculed though if massive armies can travel and in general operate as easily as heroes.
In order to make armies realistic, and to give you good reasons to use heroes instead of armies, you would have to introduce new concepts.
It just wouldn´t be done with adjusting some stats.For example you would need a measure of ressource-consumption for an army - an army of 10.000 men needs a lot of food, that most probably wouldn´t be easily available in the wastelands.
Here the previously mentioned could kick in; the food that would be available for an army would be determined by the foodoutput of the tiles surrounding the army.
For that you would NEED to assign such a food output to those tiles.
The amount of foodconsumption could also be reduced with tech or spells or such.
Another example would be organization and morale.
Paradox´es games seem to handle this nicely, at least Victoria 2 does.
Cause one problem of an army is keeping the troop together and motivated.
One big plus of heroes is that they, by definition, are focused and motivated, and that there is not much to organize with them.
Heroes thus could use hit-and-run tactics to stir up an enemies army, getting away because they would be quicker in reaction.
Anyhow, gamemechanics would have to be changed in order to make playing with massive armies fun, while not making heroes useless from midgame on.