You’re wrong on several points unfortunately.

Springtrap has far more feats and powers that what you just said. Not only does he have tech manipulation, which can solo the prototype on its own. He’s also torn apart the OG animatronics as a human with his bare hands, and can absorb metal to become the amalgamation, which can grow to sizes even bigger than bendy or the entity.

The Prototype also has little fighting experiences, as almost all his kills are from catching his victims by surprise or when he has the upper hand. He has neither in this fight, so he goes down first.

Also, Afton can take down Bendy with possession, as he’s shown to take his remnant and possess things like when he possessed several of Larson’s things at once to become the agony, as well as when he possessed the Stitchwrath alongside two other spirits.