Quote Originally Posted by HopAlongBunny
Actually it is. Present campaign, after burning Athens down...I can never train or re-train more than one unit; after placing one unit in the que, all selections grey-out. The part that is a little less than believable...with a pop of 400 it has the largest trade income
If I understand what you're saying correctly, then I have to contradict you ;)
Right now it's not limited in the way I was suggesting in my post above; the _only_ limitation right now is what you're seeing, that you have to have over 400 (or some similar number) men in order to be able to train _at all_. But whether you have 800, 8000 or 32000 makes no difference whatsoever in the number of units you are allowed to train (as long as the population doesn't go below 400, of course, but it's practically impossible to do that in a city with a few thousand population). _That_ is what I was talking about.

I believe that gives you a bit of an advantage over the AI, since it will never be able to exploit this to the extent a human can - hell, it doesn't use full stacks as often as it should to begin with ! (remember all those 2-3- unit stacks that you meet all over the map, and the continuous trickle of crappy armies that come to attack your city every turn ?).

I also believe that because of the faulty way the AI is managing its armies, i.e. not merging them when it could easily do that, that the retraining of a unit and preserving entirely its experience gives you yet another extra edge against the poor AI.
Why ? Well, because it's trivial for you as a human to get very experienced units, very fast - precisely because the AI keeps offering you an infinite amount of 3-unit stacks for you to clobber at your convenience, gaining experience without any significant losses.
So in that light I believe this is slightly overpowered. It would be more balanced if the AI were able to use full stacks properly - in that case I reckon we could leave the retraining in 0 turns and the preservation of the unit's exp as they are...