The warriors and thunder both have 2 rookies who are a major part of their winning season this year. I think the key is to pick guys who have a great feel for the game and don't have any major weaknesses that they still need to develop.
I'm not saying that's the direction we should go, just that it is possible to get better while using rookies to fill rotation holes.
OKC has SGA, Chet and JWill, all of whom have star potential. Once you've got that in place, then sure, draft complementary pieces like Cason Wallace.