Just throwing my 2 cents in, I honestly just wish Summoner felt more along the lines of Yuna in Dissidia. She did not "summon" them in a traditional sense but they appear only a brief moment to unleash certain attacks. Much like in games past minus the lengthy cut scene each time. I'd say let SCH have the Bio/Miasma and let us go into a more primal type. Like allow us to open a portal in which Ifrits head pops out and breathes fire in a cone, Ramuh brings down a strong bolt of lightning on a target and so forth eventually working our way up to Bahamut in 60+