In reality, during the first three weeks of the game, the main hero will have a particularly large number of creatures of levels 1-4 in their army, while the rest will either be built in the city or their numbers will not yet be large enough to deploy them on the battlefield and waste them there. At least, that's always how it works for me.
However, in Multiplayer, games generally end in almost a month, and this raises a serious question. The question is mainly related to the fact that in a month, all the starting resources will be spent on building up the city, and the new resources coming from the mines will not yet be quite enough to buy a full-fledged army. In this case, we will either end up staying in our own castle until the mines bring in resources, or we will finish the game at the same time, but using creatures of levels 1-4 on average, while suffering huge losses in the Global Offensive. In this case, having a hero of a high level will no longer help; in the end, the one who accumulates more resources and buys creatures of levels 5-6-7 will win, and not the one who runs around the map with low-level creatures until they are completely wiped out somewhere in a treasure.