Please forgive me if this subject has come up before but it has always seemed odd to me that the arcane magic based Mages Guild mages summon daedra or the undead when daedra are the enemy of the empire and necromancy has been expelled from the Mages Guild. The use of soul gems, by Mages Guild mages also seems contrary in this case. I do not like the idea of soul gems, soul capture magic, anyway but this and the summoning appear to be inconsistent.
Mage Guild mages, those of the Arcane University, could summon creatures such as imps, trolls, spriggins, wolves, rats, minotaurs, along with other magical wild creatures. They could even summon such as heroes of some kind.
As for energies, arcane mages need to have another source to recharge devices and personal majika.
As for soul magic, for recharging, I suggest it be replaced with the theft, and use of, life energies and that only necromancer use it.
Daedric mages summon daedra and necromancers summon the undead!

Such drastic changes would be
Such drastic changes would be unacceptable.
Summoning of daedra by mages is even used in particular quests.
Also mages are alike controlling daedra.