Also, note that the commitments you see on PG are only high school seniors. Many schools add in JUCO and other transfers, they are also "incoming" in a given year. One P5 had just over 10 players committed as of NLI signing day last fall; by this summer, their total number of incoming was over 20, including late added high school seniors, and transfers; they have 20 returning players listed on the fall roster. So even if you had been watching carefully, you might not see it all. I guess one possible way to gauge this is to check how many of their juniors and seniors on last year's roster were transfers.