Orcs have no magic. Warcries.

I mean the traditional concept – let's remember the fourth game ;-)
After all, the fifth game continues the series after the fourth part, although, I don't deny that it resembles the third game more.

The fifth game was not originally connected to the other parts of the Heroes series; only minor biographical hints are what connect the fifth part to the rest of the world... There's no need to remind everyone that not so long ago, everyone was working on how to connect the fifth part with the rest of the universe – I didn't see any specific, significant results... :)

Regarding magic, I don't think anyone has the right to prevent players from leveling up any of the four schools of magic. Most likely, the developers will simply reduce the percentage probability of a skill appearing when a hero reaches a new level to a minimum... that is, like with the Undead's Leadership skill – the probability of obtaining a skill from the skill wheel is 2%, the same will be for the magic schools for Orcs... :)