In my experience, I can see good things and bad things about having a mage/warrior duo. Some good things would be that the damage output would be greatly increased. Adds could be handled with great ease depending on the amount of adds. The one thing I would worry about is that there is no healing. It's almost like having two warriors. If you're going to group them, I would go easy on the nukes unless you have your warrior's taunt maxed and have some hefty hp buffs on your mage. Mage pets are mainly meant for tanking. Your warrior or mage pet would be much better off with a true support class. Cleric for healing, shaman for slowing/haste/buffs, chanter for slowing and hasting, druid for healing and skinspikes... you get the idea. It can be done, but there are better ways to do it if you have the classes at your disposal. Hope this helps!