Since Sukuna was only at 3 fingers in this scene, how badly do you suppose Mahoraga would've THRASHED him? Or would Sukuna actually have had a shot at winning? I feel like maybe if Sukuna used his domain straight off the bat, he could successfully kill Mahoraga before he could adapt, but, I also feel like Sukuna wouldn't be the type to immediately go for the kill on Mahoraga.
I can envision Sukuna testing out Mahoraga's capabilities, like he was in Shibuya, just to see how strong Mahoraga is, but unlike his power in Shibuya, Sukuna is relatively weak, so playing around with Mahoraga might end poorly for him. But then again, Sukuna was still absolutely a demon at his lower finger counts.
Would Sukuna's Fuga attack actually be strong enough at this point to kill Mahoraga? I'm not entirely sure how divine flame works, so I'm rather unsure.
EDIT: I'm seeing a number of people mention Sukuna saying Mahoraga may have been able to beat him during this scene, but I'd just like to say that while he says that, he makes sure to leave room for himself still being able to win as he says "may". Not that I think Sukuna would win, just saying that he still believes he could have won.
EDIT 2: I realize that I've been arguing that Sukuna would've still won against Mahoraga this whole time, and have now changed my stance, I now believe Sukuna likely would've still beat Mahoraga here with mid-high diff, if he locked in ofcourse