That's still a massive amount of players who are under Chelsea's book. Some youth team players labeled as a Chelsea player but loaned out and still fielding a competitive academy at a couple of levels. Many fringe squad players loaned out year after year. They must be on lower first team salaries for other clubs to easily attain their services. For example, Matt Mizaga was a top MLS defender and made like 5 appearances for Chelsea, but has been loaned out for 4 consecutive years. Bayakoko joined from Monaco for approximately 40M pounds, wasn't good enough and has been quite easily loaned out for 3 consecutive years. RLC, Kenedy, Piazon, Barkley, not sure what Drinkwater has been up to, kalas, rahman, etc
It's an insane amount of players signed then just revolving door of loans under Chelsea's book.