If this wasn't a Final Fantasy title no one would complain about the Summoner but since it is to give the Summoner more of a Final Fantasy feel the Egis should be replaced as the Summoner's pets with weaker and smaller replicas of the Primals with slightly tweaked abilities.

Ifrit- replace Eruption and Radiant Plumes with Fire II and Fire IV
Titan- replace Weight of the Land and Goal with Stone II and Stone IV
Garuda- replace Eye of the Storm and Great Whirlwind with Aero II and Aero IV