Why not a 4-star?

When coaches recruit players that they figure are pretty certain to be one-and-dones, they do not get much bang for their buck. What if, instead of that strategy, they recruited players who were mere four-stars (assuming fewer of them would go after one year) and even very good 3-stars. Then there would be a reasonable chance that those players would stay for multiple years, maybe even all four, and the program would get a lot more good out of them. I would think that a lower-tier 4-star, with four years of development, would be as good as a 5-star who still has kinks in his game and immaturity issues.