Lamb has/had 2 advantages over Seth
1. He's 2 inches taller (yet still kinda undersized for a SG).
2. Seth Curry is older than Lamb.
And even with Lamb, he wound up going mid 2nd round (he was projected to go higher).
Jimmer didn't get drafted solely off of his shooting. Jimmer was an extraordinary scorer in college. His defined position was a weakness (and his defense), but Steph actually set a precedent that allowed teams to be a little more comfortable with the idea of taking Jimmer. Jimmer honestly could probably still succeed in the league, but he's in the worst spot to showcase himself in Sacramento.