I think Menzies was going International out of necessity. Not a lot of domestic ranked recruits lining up to go to Las Cruces. Thought I do think that going after the 6.something billion people that don't live in the USA probably has a few gems out there, but at the end of the day, the best players do seem to be home grown.
I think that it would be awesome if the NBA could recruit and have a guaranteed contract when they leave college. Which NBA team would not love to have one of their recruits get another year or two under Coach K? There are seriously very few recruits who are one and done the vast majority would benefit from more time in college. Making it to the NBA is very rare. 60 are drafted every year. The problem arises from how long a career can last. How long did Kobe or Duncan play? 20 years? I would guess (I don't want to look it up), the average career is around 10-15 years. Football (not kickers) is much shorter and they have a lot more players.
So, my suggestion would be, have another round in the draft, but the teams could write contracts to pay the kids guaranteed money "later" and they could stay in school and play more thus getting valuable experience. I don't know if having a future contract for future money violates the amateur status. Probably, I don't really know.
Also, when the kids are in college they have to go to class. In the NBA they no longer have to go to class and just focus on basketball. Plus they aren't limited to practice times, etc.
Lots of pros and cons each way.