The most difficult alternative

What I mean is, when playing as Haven and capturing undeveloped Chaos castles, it's more advantageous to build Hydras. They offer the same illusions and teleports. With a Nature and Life mage, you can teleport into the thick of enemies, followed by Guardian Angel and Antimagic from above. Or use a different set of spells, depending on the opponent, but always starting with teleportation. With a Haven mage, you'll never be able to drown a Hydra or Naga in sand. ;)