Getting armor, weapon and valor upgrades via retraining

[Shahed]

That's a very useful post, thanks. Excellent explanation of how to merge units.

Now, that is exactly what I am doing, and have been since I noticed this valor 'upgrade' when I merged two units at random. So now I have already merged units and am putting them through the retraining mainly for the armor upgrade. There are enough units in the unit pool but it's still not working.

So this means the reason is not that there are not enough units in the unit pool. Actually if there are not enough units in the unit pool, you cannot retrain for manpower at all. In my case they are being retrained for manpower but not for armor.