RTF is a global modification that replaces all towns in the game.

Very strange distribution.
Phantom, regeneration, blessing, dispel magic - fire?
Scatter, slow, enthrall - water?
Wall of swords - air?
Vengeance, beam, mines - earth?

I recommend remembering the spell distribution from Heroes 3.

Ten pages ago, I already asked this question - they excused themselves by saying that skills that give mass versions of spells cannot be changed (for example, stone skin is earth and evasion is air, but both are for the one who grants protection, and similar problems).

Added 2 minutes later
Therefore, I believe that the distribution into elemental schools is irrational.