I'm going to go with Terminators on this one, though I never really watched Hellsing. Though I'm sure that the Letzte Batallion have a huge increase to strength, speed, durability etc. due to the fact that they are Vampires and they do seem to pack a hell of a punch with the weaponry they carry. I am doubtful that they can overcome a large squadron of super durable robots whose sole purpose is killing and also have quite a large amount of strength and durability. Being uplinked with one another the terminators all know exactly what is going on in all points on the battlefield, with the extremely advanced AI and processing power they each have I could see them easily coming up with a clean and efficient way of destroying their opponent in mere fractions of a second.