I think taking bigger classes helps solve this issue since even if you lose some kids to transfer, typically a couple of kids will stick it out all 4 years and you'll have experienced upperclassmen on an annual basis. If you look at this year for example, a lot of players were thrown into situations they just weren't fully ready for and there was zero quality backup for them. ONO didn't have any post backup, Griffin was forced to play big minutes in some games that she wasn't ready for, and Williams shouldn't have been playing 35.6 mpg.
A lot of schools have gone the transfer and grad transfer route to shore up any holes, but that hasn't worked well for Geno so far.
If he takes on average 4 person classes and endures transfers, the roster may whittle down to 10-11 on an annual basis with a team makeup of something like 2 seniors, 2 juniors, 3 sophomores and 4 freshmen. In that scenario, you have veteran players who know his demands and his system, plus an influx of youth playing in smaller role unless they're studs and learn his system quickly. The freshmen and sophomores who aren't as good but want to play leave for their own greener pastures, and the best players stick around and become the experienced upperclassmen. Might not be exactly that breakdown, but wouldn't be surprised if that's his ideology going forward to help prevent situations like the 2019 and 2020 seasons where he really had zero quality depth.