The way Binder works in the books, is that he can have as many summons as he wants out of combat (he summons pretty quickly) to some limit likely based on skills/focus items/etc or even more likely by high concept or other aspect, but in combat he summons one dude per exchange.
That doesn't look like Evothaum to me at all. That looks like plain old Rituals, where he's just banging out a whatever level of shifts he can generate based on his conviction, complexity based on his skills, without fussing with circles, declarations, blah blah blah.
Just give him rituals, decent conviction, decent lore, focus items to boost both so each exchange he can pop out a dude for a scene and call it done. You don't get tired with rituals if you don't burn power higher than your conviction. He can always burn some mental stress and tag an aspect or something if he wants to bang out more than one guy per exchange.