I would drop it from Arcanist and retool Arcanist to better suit Scholar.

I would move it away from a pet and DoT class and as it isn't an Arcanist no more Soul Shards/Aetherflow, a Summoner isn't a Warlock.

I would base it around a new Aether Gate gauge where you cast nukes in a specific order to open different gates for different Summons. Large variety of Summons, each with a cooldown and have a small selection fulfilling each different role, ie; single target damage, aoe damage, debuffing, etc.

Summoner should be about, well, Summoning. It should be flashy, calling down Shiva for a 3-4 second Diamond Dust animation, then going back to prepare for the next. Summoner should be about nuking with Summons or fading into the Aether to become the Summon. The last thing it should be is a Warlock-style pet class where all of your Summons are glorified imps.

It is amusing because XI and XIV are two games that really get Final Fantasy, especially post-Sakaguchi, but they both botched its most iconic job by trying to turn it into a pet class. Summons are not pets.