I can see the initial fight going to Black Adam because Superman is susceptible to magic and Adam could take him off guard. I think they should just use the Superman/Shazam: Return of Black Adam as the blue print. No clear winner until Superman and Shazam team up to take him down.
I can’t imagine Zaslav allowing Superman to be humiliated when he’s all about the bottom line and he knows that the Superman brand can still make them money.