I didn't want to go the sustained spells/autoattack route with arcane warrior, so I had no need to pick up anything but Combat Magic. Combat Magic is just to allow me to equip massive armor, as I find it more suitable than the mage only equips.
Second specialization was Blood Mage, but I only took it for the stat bonuses. I cannot use Blood Magic, as it ruins my 100% damage contribution. (because friendly fire damage is counted against you)
I'm basically playing this as a normal spell casting mage, as opposed to some variation of a warrior. I'm using heavy armor for armor and mana regen and fatigue reduction, which allows me to sustain spells without having a large fatigue and offers good mana regeneration to counteract the loss from Spell Might. (which oddly mage only equipment for those same slots does not)