Doctor Brimstone says:
"Assuming that Superman and Adam are somewhere close in power (there's obviously a lot of disagreement), I think BA has a significant edge because of Superman's various weaknesses coupled with the wisdom of Zehuti... BA can simply KNOW things he needs to with this power. For instance, where some kryptonite is, or a source or magic... And is there normal sunlight at the Rock of Eternity, where BA could transport them? Martian Manhunter didn't seem to be too much trouble for our man in black, and Superman has stated that MM is one of the few on earth he wouldn't want to face. It's worth noting that BA is supposed to be more powerful than Captain Marvel was, (at least before taking on the role of Shazam) because Marvel shares his power with the other Marvels, and he and the Kryptonian have squared off as seeming equals in the past. "
Unfortunately, it's DC's editing and bad writing that don't show martian manhunters true potential. you only hear bout it in panels when someone like supes mentions it! and superman wasn't around during WWIII, otherwise, there wouldn't have been WWIII! and if BA had all that wisdom, then he wouldn't have massacred that nation and tried to take down most of the DCU! just cause you have all these abilities, ie wisdom of so and so, speed of so and so, doesn't mean you your known for using them all the time! if that was the case BA would be suprememe and no one would stop him!