- A reference guide and manual in Russian for Heroes 3.

Or maybe the number of upgraded units isn't calculated as a percentage of the non-upgraded ones, but depends on the number of hit points of the upgraded units relative to the hit points of the non-upgraded ones? (i.e., the number of non-upgraded units depends on their strength and the number of units killed, while the number of upgraded units depends only on the number of non-upgraded units, converted to hit points, plus rings and potions are also taken into account).
Did I make myself clear? :) :) :)