Exactly.
Key rotational bench player.
He does not have what it takes to be a starter and probably won't.
Also, I could care less what he has done overseas. It's a different game there with lesser talent.
He doesn't have the mid range game, the ability to take it to the hole and finish, the defensive ability to be a reliable starter. Too many warts on his game.
He will, however, be a very good bench role player his whole time in the NBA and there is nothing wrong with that. You seem to be as infatuated with his game as he is himself. Which is probably why he wants to run back to Spain where the talent level is much worse and he can start and be a star.
In bold, his finishing ability, happens to be perhaps his greatest strength... maybe you aren't very familiar with his game?
That being said, he could start at SG but would not be optimal. He can be a really great 6th or 7th guy, and that is very valuable. This is for sure, but since we have not seen his potential and he is yet to enter his prime, I would not rule out him being a good starting SG, there is still the possibility for that.
Also don't be surprised if the "lesser talent" of that Spanish team Rudy plays on beats Team USA this summer. I wouldn't sleep on international play and especially not the Spanish team.
As with all internet arguments, both sides go too far. Rudy is not a great SG starter, but would be a great bench guy. He can really play.