You saying this out loud first makes me think it is ridiculous...but then I think about it a little, and realize that, with how ridiculous his growth rate is, that might be plausible.
His growth rate is so stupidly insane that even the 3S rank adventures who are literal, walking natural disasters, get freaked out by it. Obviously, they probably had a much higher starting point than he did, but I do think that implies that his growth could very easily and quickly lead to him reaching their level.
I mean their entire purpose in training him was to find a husband on their level, so we know that eventually he has to reach that level