I think all of those were in prime at that age.
I may even add "Shanks and Mihawk" into that list as well.
I think so far, the ONLY CONFIMRED people who were at late 30s or early 40s at not in prime, are the admirals (Kizaru/Akainu/Aokiji) as they were vice admirals.
But Garp, Roger, WB, Oden, Shanks, Mihawk. All of those were hinted to be at their best at 37-42 years old
With Big Mom and Kaido. There is NOTHING confirmed on either honestly. So, they are like a toss, it depends on however Oda wants to play it.
I've seen some evidence with 40s being their peak, and some evidence that after 40 they still got stronger. So, it's a toss. I don't know for sure