and you can pretty much check off the first 4 you mentioned. They were already here and not recruited over, they just weren't Cals.
Yeah, these 4: Galloway, Pilgrim, AJ Stewart, Donald Williams
Those guys can't be used in this discussion, in my opinion. They weren't Calipari recruits.
Dodson had off-court issues and was going to be gone after 1 year, either way. Poole might be an example, but he needed time (years) to be ready to contribute at an elite level. Harrow had some ability but mentally couldn't handle the pressure of leading a UK team. I would grant you Wiltjer. If he had come back, he had elite athletes at every position to compete with. But Wiltjer could have stayed and contributed because he had a skill that was needed, 3pt shooting. Matthews could claim he was recruited over, but that's only if you count Gabriel as a small forward. Otherwise, Matthews probably left because of the returnees more than the incoming recruits.
Edit: this past season was a golden opportunity for Matthews. Briscoe was playing out of position at the 3 and nobody else really stepped up. Matthews should be a true small forward but couldn't earn the spot. His issue isn't that he's been recruited over.