He reminds me a lot of Paul Millsap early in his career. Randle has become a good individual defender, is an excellent passer, and a decent rebounder. If he could develop some sort of jump shot than he'll become a rotation player for a good number of years. Additionally, his shot looks good, it's just a matter of consistently sinking those jumpers.
Nance needs to learn positional offense. He likes to cut a lot, which is cool, but it tends to disrupt offense and clog the lane. I think both guys will become good NBA players, though; they just need to improve on some small stuff.