I think you're over/under-rating Bertans/Daye, repectively. Bertans isn't as great an all around shooter as you state. He is also not a great ball-handler, and his defensive weaknesses are obvious to many. And, this is against non-NBA compe ion. Daye, despite his short-comings, has been performing against NBA compe ion. If you read this critique of a player:
"Haven't seen Hanga play this year but I do not agree about Bertans. I saw quite a few Partizan games this season and saw nothing at all in him that makes me think he will ever contribute at NBA level. While he did shoot 47% from 3 in Euroleague play, he only shot 22% inside the arc. He is too weak to guard 4's, too slow to guard 3's and really doesn't look like he is interested on the defensive end. He is an awful rebounder. Offensively he is extremely one dimensional, averaging 0.7 assists and 1.2 turnovers per game and really doesn't put the ball on the floor well. In a crucial game against Bamberg he had 2 costly turnovers at big moments in the game."
...and consider the question: Would I be in love with that player if I didn't already know his name? Daye was recently criticized for shooting mid-high 30% over a small sample from inside the arc against NBA compe ion, even though his career numbers are higher. Your much more versatile shooter shot 22% over a season of Euroleague play against lesser compe ion. Daye is a much, much better passer, and decent at putting the ball on the floor and driving to the basket, dishing, drawing fouls, or scoring. Daye is a much better rebounder, currently leading the summer league team in rebounding. Both of their defenses are suspect, but Daye's has been decent in summer league. I would like to see Bertans get a shot, but the notion that he is so ready that we need to leapfrog him ahead of other project players like Daye is not reasonable. He has plenty of improvement to accomplish while Daye gets his shot this year.
The Spurs seem to continue to agree that he is still not ready as he is signing a new 3 year deal with a new team:
http://projectspurs.com/2014-article...-baskonia.html