I believe they can get there.
To me, Skywalker has better hands than Rudy, so his offensive game feels a bit more solid. The impact on D will take some time, but I believe he has All-NBA potential. He needs to work on some things, such as FTs and a midrange/three point jimmy to open things up for Lauri, Hendricks, and Collins to work, but it can get there. The fact he was a ROTY candidate despite not being an offensive savant is very, very telling.
I think Key could be a Dame/Don hybrid of sorts. He needs to work on his defense, but again, there's a lot to work with because of his athleticism and willingness to try. SL sample size is small, as is college, but it feels like he passes the eyetests pretty easily to me. Only a few games in and he's gotten such a handle on the offensive side of things that there is nothing left to prove there. He's also only friggin 19. I've no doubt he's the PG of the future.