I'd say he has a good "fight" IQ but no he's not quite smart. He has also "not applied himself to perfection" in terms of his powers as there are others who have progressed just as or faster than him in terms of growth with their powers such as met (or any twins, or the superhuman "exception" who got to level 5 in a month) so would they be applying themselves beyond perfection?
Every one of MCs high school friends think it's werid that MC is going to R&X, MC openly admits it's only because of his daddy (blackmail), he falls asleep in class and has been doing so for YEARS, and then you have all the examples of stupidity in game like him 100% convinced amber was a camgirl because "Blue fingernails", most of the "smart" (beating valravn honorably, not getting caught in sin infiltration etc) are player choice dependent and shouldn't be attributed to every single MC (like corruption)
Edit: Also without stupid dumb luck (syla being MC mom while also being connected to an apostle that can help you train while drugged up) MC is missing 1/3rd to 1/4th of his power (or whatever 120/your power is) that really doesn't seem like he's getting all his power through "him applying himself"
1. No one who has good fight IQ is stupid. You
need to be smart to understand fighting well.
2. All your examples of superhumans superior to him make no sense:
- There's no reason to think Met is superior to him. They've both delved pretty deep into their powers and I don't think it's obvious who would win in a fight if MC wasn't particularly weak to lightning.
- The twins reached level 3 through a combination of their twin connection and an evolution serum. Nothing about their accomplishments indicate above-average intelligence, and anyway they got destroyed by the MC even though they double-teamed him and reached level 3 not that long after him.
- Evolving doesn't mean you're smart. It just happens as a result of some form of pressure. Henri surviving and not completely turning into a monster as a result of his rapid evolutions might say something, but there's nothing that says MC couldn't do the same. Even if what you're implying was true, though, Henri is literally the only example of this. That would be like saying someone isn't intelligent because they didn't come up with the Theory of Relativity.
3. Not sure how falling asleep in class indicates a lack of intelligence. If anything, the fact that the MC could graduate despite not even paying attention in class means he's probably at least above-average.
4. Him thinking Amber was the camgirl is not emblematic of low intelligence though? Smart people say and do dumb shit all the fucking time.
I think the problem here is that you just don't have a good understanding of what intelligence actually is.