As I said before strength is not the determining factor. Hulk is stronger than Doctor Strange right? So that automatically means Hulk will win?
No. Because of Strange's magic.
Steel has technology to create Boom-Tubes, absorb cosmic energy, manipulate the electromagnetic spectrum, create forcefields, etc.
Colossus is simply outmatched because he only has strength (that's weaker). That's it. Steel wouldn't even bother to physically confront Colossus. He would just attack him from the air.
Look, it doesn't even matter, right? Steel's side has Batman, and we already know that Batman can take Galactus and Thanos at the same time with prep, no prob. So Steel can just take a vacation while Batman polishes off the competition by himself, really.
This is just a warm-up for Batgod, after all, who will then go on to school Spectre for some real kicks.