Yes, they are trained so they can become batteries in Magitech devices!
Just kidding, well I think it really depends on what the Tinie plans to do as a Mage, I can't see a Mage Tinie joining the Isolon Fist as a combatant (come on...a three inch person against 100 feet gaints? They are so small that they will get lost in the inner creases of the gaint's belly button) But that's not to say a Tinie can't join the Isolon Fist as some kind of surport, perhaps a medic? They can closerly examine the wounds of their bigger teammates and deliver pricise healing magic.