Hypothetically I don't think they would've been a serious threat to Murphy at the top, not with all that Dogs are bringing back, due the Cats being too one dimensional offensively. In reality Murphy will have their own major question next season with the loss of Murray in the backfield (his loss could seriously effect what will otherwise be a very loaded team) but since were talking in hypotheticals, and each team having all their guys, Smith and Crowder are still playing for Murphy and therefore the backfield question is much less pertinent. I do think the 'Cats would've been a surefire top 3 team though and a serious contender for 2nd.
As far as the 2022 team being Andrews best in decades, I couldn't say but I do know they should be a very tough out if they stay together. And they will have another skill weapon in that age group on varsity with Charles that will be nice for them. With that said they will likely have the same question mark about being too one dimensional offensively that the 2020 team would've had.
The young man you mentioned will be ineligible due to age I believe 2022. Varsity is a different animal than JV. This Murphy group of freshman will be much improved in 3 years and also has a solid ground coming behind them.