Comparisons are quite difficult. People tend to compare international prospects to international nba players, what in my opinion is not a good practice. Rudy Fernandez is more a poor-man Ray Allen. Worse shooting skills but improving (he has the skills but need some polishing), similar body in 2/3 years time (Rudy is still a little bit skinny) and perhaps better passing skills for Rudy. Maybe other that could resemble Rudy's basketball is Brent Barry
Rudy is just 19 but even though he is a go-to guy, he wants the ball when he is needed although his passing skills are quite good. He is averaging something about 4 apg, but in FIBA baskets assists are more strict to be counted, but as a reference he is 4th in assists in ACB, and the first SG. Rudy has a winning attitude and he is really coachable and his basketball IQ is absolutely high. Now he is having some problems with an injury but it seems nothing serious.
In Europe for a SG his leaping skills are above average, but nothing special if he moves to the NBA, Ginobili is much stronger in this and in many other things. Rudy has a good defensive attitude but needs a lot of improvement, at the moment when not defending zone he could be a liability, at least during the time he gets some more strength.
I haven't seen most of the US prospects, but according to my way of seeing basketball I would draft Rudy earlier than Fran Vazquez or Splitter, and much earlier than Gelabale. I think it's easier to find a PF with some skills rather than a coachable SG with talent, potential, winning attitude and team attitude