Secondary skills in Heroes 3.

to samadura
By the way, regarding the second hero, as well as the third and fourth... if you're going to create them, the Necromancers have the best conditions for it. By equipping the army with vampires and other creatures, you can increase the number of skeletons without paying too much attention to the number of "supporting" units. This way, you can get several heroes. Moreover, Necromancers are slow, and it's better when several armies clear out neutral territories simultaneously; the skeletons grow faster.
In any case, when I play as the Undead, I always create many heroes. Then, each of them can engage in a major battle (of course, you need to merge all the armies under the command of your favorite hero beforehand).

READ MY POST MORE CAREFULLY!!! "MAIN HERO"... there should be only 1, and you're writing something unclear... I already know that there should be many heroes.
And regarding collecting skeletons, the main... the lion's share of all skeletons still comes from the main hero, no matter what... he has the army and the necessary artifacts... and those that run around separately and collect...
But this takes time; you'll definitely send them out no earlier than the first month + you'll have to detach them from the main forces, at least with 10 upgraded vampires + while they are learning Necromancy level 3 + there is a high probability that they will be defeated somewhere in foreign lands with those 10 vampires = at best, half of them will return home, and those 300-500 skeletons that they collect for you won't make much difference (Vidomina or Izra in a "good location," and even with the right artifacts, can raise that many in a couple of days) and don't forget about time... it always takes a long time to travel with Necromancers due to constant battles, and if you have to pack skeletons with a couple of additional heroes with "weak troops" in addition to the main one, then imagine how much time it will take... who will like it if you take "an hour" to make a move?