Thing vs Rockslide - who would win? I bet on Thing but Rockslide's reforming ability may make some difficulties for him.
Rockslide. He's not a golem iirc Beast mentioned that his mutation is not that he is a giant golem but more on the fact that he restructures himself from the materials around him. And considering there aren't anything specific rules to this battle I'm assuming this is in an open location with the winner going by ko or death. Now Thing would have him beat in terms of fighting skill, field combat knowledge but Rockslide can't be beaten in the conventional ways. Now this of course is if by KO I mean unconscious. However in the event that we're talking about KO as in unable to fight for a certain period than Thing would have a better shot at it if he could pummel Rockslide enough that it would take quite some time for him to reform but it's been proven from the New X-men comics that Rockslide can reform rather quickly and with whatever materials are around.
Seriously though it'd be easier if the battle terms is more specific. In terms of combat there's nothing Rockslide can do to harm Thing. But then there's nothing Ben can do to harm Rockslide. RS got completely obliterated by Nimrod and that didn't stop him from existing.
The Hulk is a 100+ tonner
Colossus is a 100 even tonner (without Cyttorak)
Thing is a 75+ tonner (though this was as of 2009, I've always been under the impression he's slightly above Colossus' strength and durability)
I would argue with anyone who claims Rockslide is anything more than a 40 tonner. Literally couldnt hurt Thing if he tried
Thing CURBSTOMPS Rockslide. He is superior in every way. He is vastly stronger and more durable. Is a better fighter and has more experience where it matters. Bashing him to nothingness should be more than enough to count as an incapacitation. Or Rockslide gets BFR'd.