Nature Structures

Here, Charm is very useful for heroes; I've played and know. Regarding summoning, you might be right, but it's rarely used. Even if you don't need a particular unit, why split your troops just for it? And if you need a whole squad, not just a few units? Elves or Tigers will also be summoned rarely without artifacts. As for Elementals, I don't need them at all; Mantises or the Hive are much more effective, but that's a matter of taste. If you like having Elementals in your army, then yes, summoning is indispensable and will be very helpful in increasing their numbers. But, in my opinion, we should end this discussion because it's pointless. P.S. Regarding the phrase you didn't understand. In versions before Equilibris, if you join units under the effect of Charm and you don't have enough space, they will stand next to you as a separate unit without a hero. I'm not sure how it works in Equilibris (I quickly installed Equilibris on them). In Equilibris itself, if you accept units under the effect of Charm and you don't have enough space for them, they either return to their previous squad (to the enemy hero or to the wandering units) or simply disappear (I didn't fully understand, I was too lazy to count). By the way, it's interesting what will happen if you swap units, remove one from your army, and put a "charmed" unit in its place.

Added 2 minutes ago

Sorry for the silence. I was in the hospital for a week:( :( :(

Don't apologize; this is Heroes 4, and it's often quiet here. I hope you're better now and won't need to go back to the hospital