Out of interest, and because I'm apparently less lazy than a journalist who's job is to do this (took me about 15 minutes). And because Bath were used as the example of the grossly inflated squad size.
As of September 1st 2023, Bath squad had
27 players aged 24+
25 aged 20-23 (of whom 6 are match-day regulars, so not exactly "transition")
19 aged 18-19
Had these regulations been in place ahead of this season, then realistically, we wouldn't have picked up Faiva and Owens both from being unemployed, probably wouldn't have been able to sign Stooke.
Realistically then, to fit the senior squad into 35+12, we'd have had to lose 4-5 "senior" players (depending on Stooke) - who'd have ended up unemployed. I fail to see why losing players to the sport is for the good of the sport. I also fail to see how spending £6.4M on 47 players is more sustainable for the club than spending £6.4M on 52 players. The chances are, those 5 would have been recent graduates from the academy (or players still in the academy), and probably front row players, because they just take longer to mature, and are more unpredictable for success aged 19.
Then we'd have to cull 10 from the academy - to what benefit? where would they go to?
So any late bloomers - or even on-time bloomers, will basically be lost to the sport, for no benefit I've yet to see.
Oh, and before anyone brings up the "from their academy" bit of the "transition" group, we can hit a full 12 who are still IN the academy.