Guys like Milne, Moore, and Wall aren't going to do much to help us succeed at a high level. You can tell a lot about how good a recruit is by what kind of offers he had.
For Milne, his best offers were to Army and Air Force. Neither of those schools is known for producing great wide receivers.
For Moore, his best offers were to SUU and Weber. Not even USU was willing to use a scholarship on him.
I couldn't even find a profile for Wall on any of the recruiting sites.
I agree that getting FCS level players to come to BYU as walk-ons is probably a win, but the odds of them actually becoming meaningful contributors, especially early on in their careers, is very low. These are guys who will play on the scout team, play special teams, and maybe, maybe crack the rotation as seniors. That's my expectation for them, and I'd be shocked if they do anything more.