This is all true, but the one sure-fire way to land a potential superstar is to draft him and hold his rights during his developmental stage.
Indiana Pacers.
Remember, Paul George was a #10 pick, Hibbert was a #17 pick, Lance was a #40 pick. They developed those players well and made a very good signing in David West and traded for George Hill (they could have kept Kawaii Leonard also?). Goes to show what careful drafting and planning can do.
Granted this is not normal, but with a hard(er) cap coming it's also not impossible.