They were "combo guards" in college but they were drafted to play PG in the league.
Waiters doesn't have PG skills. He's a 6'4 ball dominant volume scorer (and they already had a ball-dominant volume scorer on the team). He's smallish and doesn't really defend. It just wasn't a good pick at #4.
In the long run I think Waiters is going to end up being a sixth man-type guy. Like a spark scorer off the bench who will score some points and probably give up some points on the other end. But again, you don't take that kind of player with the 4th pick in a solid draft.
And who would that be because Irving is no volume scorer. Ellis is a volume scorer, Brandon Jennings is a volume scorer, Nick Young is a volume scorer.....
Irving is not.
And I hate this undersize comment. The 3 dominate SG in the league are Kobe(6'6), Harden(6'5), and Wade(6'4)
Only 1 of them is 6'6. In terms of scoring as a 6'4, its not as big of a deal as some of you make it seem. The top defensive SG are 6'1 and 6'4 respectfully. Stop making so much out of the size and just measure based on the actual basketball skills