Notes

You make valid points, but I heavily doubt they went training in a similar fashion. I'm not sure on this but CP0 was written as being the strongest CP unit? (don't remember well since this was like 2 years ago now). So you could assume they got trained by some really high-end people; but is that really enough, even assuming they had top-tier training?

Not everyone in the OP universe trains at the same pace; Coby developped ridiculously fast for a marine (when we compare him to Smoker, I think you can see just how insane his growth has been) and the Strawhats, in less than a year, managed to accrue some of the most batshit insane feats of strength for rookies who didn't know Haki and barely had any devil fruit users in their group.

On top of disproportionate growth (even if we're not factoring age here, in which case the SH would have a base advantage, having a young and fresh crew and a skeleton) all of the crew had extreme individual practice on their