Hypothetically: which units from Heroes of Might and Magic II would you replace?

I've been thinking about this for a while: why don't the developers of Heroes like peasants so much? Why not increase their growth rate by another 15%, while keeping their other stats the same? Skeletons, for example, rely on numbers, but they aren't that weak for level 1. And they appear out of nowhere. But there are too few peasants, and their growth rate is too low to stand up to anyone.