Drafting is always a game of chance. If you scout more players, you get a higher chance of getting the better player but there is no guarantee that you'll get them.
I got lucky in this year's draft because in my rankings, the player I put in #1 also had a role player potential and is 19 years old but someone drafted him ahead of me. I'm sure that the one I put as #1 had a power forward position and there is only one power forward drafted before I got to pick.
But I got a 6'1 center who is 18 years old and had a superstar potential. I'm not sure now what to do since it is hopeless to train him in rebounding.
Hopefully you can get better players for the next draft :D