Alex Smith had talent. Didn't see it till he got in the right system. I think that a player that has success in any system has talent. A system can't make a good player out of someone with no talent.
What this comes down to is coaching. A good coach knows how to utilize the TALENTS of his players. The tricky part with young guys is to identify those talents. It's easy with a well known vet. You would never say that Payton Manning is just the product of a system..... but we've never seen Payton Manning play in Jimmy Raye's offense, have we?
Kaep is for real. He is very talented. Combine that talent with a system suited to maximize his abilities and you have a GREAT player.