because Lone Peak beat some great HS teams, that's hardly evidence that BYU will suddenly be much better by playing all the same players. It's not like BYU was getting kids who sucked in HS before they started mining LP.
You're right that many of these teams have multiple D-1 players. However, you ignore the fact that there are 350 D-1 colleges. A bench-rider at Idaho State is a D-1 basketball player. Which, again, was my point.