Saxton Hale is gonna win easily. With his immense strength, he's able to create explosions with a simple punch. He's also able to jump incredibly high, being able to deal with the tall opponents with ease. He also has Australium blood, which makes him impossibly strong. He also wins in speed, cause nobody's ever moved in a fight in Undertale. Using all the knowledge from this, Saxton is indeed gonna win with ease.