Think this would be good for a future update once the game is in a more defined place.

Maybe think of a unquie way they could work in ff14 as well, crisis core slot system is in my mind atm as that was intresting so it could make them random used rather than 1 summon getting used all the time and the need be quick summons that have an effect and then disapear rather than one that follow you around.
I think this would be better for the game, but its my view on it so i understand some may want an avatar /summon follow them around at times.