If he's serious, a lot of them are between 8 and 10/10.
The exceptions: Grodd wrecks him with tp, of course. 0/10 there. Carnage is probably more like 3/10. He's always needed help with Carnage. Plenty could beat Spidey - Cage, Rhino, Classic Fisk (not current), Deadpool, Venom...but most won't ge a majority in a smartly fought fight.
King Shark I have no idea. He's a Flash rogue, yeah? I don't know enough about him. And unless the Gotham crew got massive upgrades I'm unaware of, they'd be statues to Pete and would get ruined. Goblin would also get his sh*t pushed in. He's always needed a plot device to handle Pete.