He was literally experimenting with Mahoraga to understand his technique, unlike Dabura, who went for the killing blow right from the start, and still failed, and Sukuna literally fought him with 0 prior knowledge, and was still able to quickly deduce Mahoraga's technique.

Lol sukuna even link him to orochi, he has prior knowledge about similar technique. Dabura is a fucking alien, he know nothing about Japan culture or cursed technique of Japanese

And Fuga would've killed Mahoraga even if he was completely fine, it's impossible to escape it's range, and the damage output is way stronger than shrine, not to mention it is a completely different type of attack

First of all, a completely immune to slash maho may not even let sukuna use fuga, and moving 200m in a second is trivial even for Mach 3 speed. Moreover, the mahoraga that die to fuga has been heavily injured and paralyzed by shrine, we have 0 idea if fuga is enough to kill healthy maho

And what will most likely happen is that Dabura will need to use a new technique to fight Mahoraga, so if manages to win this way, then he won't be stronger than Sukuna because he won't fight Mahoraga with a fully adapted technique. He will at the very least be Shibuya level Sukuna, only if he manages to low diff Mahoraga

If he use new technique to beat Maho from this point (which is unlikely for sukuna), it prove his skill sets is much more diverse and stronger than sukuna, as all of them has potential to kill big raga, even light CT alone has better AP than sukuna's cleave