Having been inderictly sent to this topic by Oberlus, I can't resist giving my opinion about it, even knowing that player-controlled tactical combat is probably not going to happen.
First, I have to say that I played a bit of Master of Magic and quite a lot of Age of Wonders (which had trouble camouflaging that it was a rip-off of the former, whch itself was basically Civilization II with tactical combat) and AFAIK not any other game with tactical combat in it (except if Junta counts).
Tactical combat was the main interest of Age of Wonders, but it actually rendered the game nearly unplayable, which worsened on multiplayer.
This for two reasons: tactical battles took A LOT of time, and the tactical combat mechanisms actually made for not that much tactic in them. The AI played defensive, so basically either you stayed inactive too and the battle never resolved, or you attacked at a non-negligible cost as there were very few situations that allowed good tactics to entirely remove the first strike toll that defenders (especially ranged ones) where usually able to exert.
There was the possibility of full encirclement moves (though one usually didn't have enough troops to make them work to full extent) but they took so much time to play that it quickly became quite boring.
I mean, I remember vividly one battle where my leader and some rabble were ambushed by a vastly superior troop (both in numbers and quality) and I emerged with my army wiped out save for my then 1-hitpoint leader through a succession of very careful moves, and it was indeed two hours of great fun, but that's basically the only time the battles were really more enjoyable than tedious.
What I'm trying to say here is that these weaknesses are not intrinsic to the idea of tactical combat (at least a single player context) but that they were the result of how it was designed in AoW. And as such that it should be possible to design one that avoid these pitfalls.
Different tactical combat mechanisms have been evoked here, but if I'm not mistaken no one seems to have proposed a League-of-Legends style mechanism where most of the action occurs automatically and the player mostly makes action that influences these automatic-controlled fights? I would think that it probably solves at least a few of the problems evoked here, especially removing micromanagement and having a hard time-limit for each battles.
It would work well with leaders, and maybe even with a flagship mechanism that is the only way imho to have tactical combat in multiplayer (it would even allow to control directly the flagship as a sort of FPS while giving general orders to the accompanying fleet - which definitely would be quite cool though not necessarily the way FreeOrion wants to go).
I don't know if somebody played minitroopers.com either? It's not player-controlled tactical combat per se but it does a very good job at rendering what is automated combat resolution as if it were player-controlled tactical combat...
For what's not in 'Top Priority Game Design'. Post your ideas, visions, suggestions for the game, rules, modifications, etc.