I also ask the others to comment and, if possible, add, remove, or change certain aspects of the formula.
Regarding the formula, my initial thoughts are outlined above. In general, creating a single parametric index designed to account for various unrelated characteristics of an object (this applies not only to our discussion but to any other) is a whole science. How do you compare speed, defense, and growth? Here, it is necessary to "weigh" each parameter based on its usefulness in the game. And this is already a variable value...
For Galtran, for example, skeletons have a lot of value due to his specialization, but for Sir Mullich, it's the opposite – even one skeleton in the army reduces the morale of all troops. So, what is the value of a skeleton in the game in this case? And if we consider units outside of the hero controlling them, it is meaningless by definition – have you ever seen neutral creatures fighting each other? They might fight at night, of course, but what do we care about that? :)
