Shouldn't Deathstroke take a majority over Spiderman?
I know Spider-Man is powerful. But Slade was a villain spawned to take on an entire team that included Beast Boy, Donna Troy, Raven, Wally West, and Starfire. He regularly fought all of them at the same time.
He's got the tactical mind that turns the superior aspects of opponents against them. And this is way before Midnighter.
He's so adept at using his equipment that he can strike and stagger someone with the speed and power of Superman.
And he has the skill to fight and survive in hand to hand combat with Wonder Woman.
I know Spider-Man has some great showings too. But Slade has the intelligence, equipment, and skill advantages. The disparity between these two, in those areas is significant enough for Slade to take the majority imo. In other words, Slade is more dominant in the areas that he holds an advantage in. Intelligence, equipment, and skill have a greater impact on the outcome of this fight than speed and strength.