if you subscribe to that notion, I would submit that very few teams actually reflect that. The ones that do are the exceptions, rather than the norm. Gonzaga obviously would be one – they aren't going to improve their recruiting if they join the PAC-12 because they're already a top-5 national program.
Perhaps you could argue that because McKillop was an institution at Davidson already, they were getting much higher caliber players than any other SoCon team could, I don't know. I still think they have gotten plenty of guys while in the A-10 who they couldn't have gotten if they were in the SoCon. And generally speaking, if any team elevates to a better conference, it's either going to start recruiting better in order to do well in that league, or it's going to keep recruiting at its previous level and sink to the bottom of the new league.