I like the way summoners is heading towards. Demi-Bahamut was already a cool start. Now the rotation with Demi-Phoenix to fill in. In my opinion, I would say it's ok to delete egis but repleace them with another Demi-Summon which becomes active whenever Bahamut or Phoenix can't.

I overall like the general playstyle of this "summoning demi-Primals for a short time". For me this feels more satisfactioning then gameplay with egis could ever become.