Don't get me wrong, I love the depth and upside just as much as everyone. Saying we have a "surplus" is a huge stretch though.
As it stands right now, 3 of those guys are injured with no timetable for return (Julio, Perez, and Gant), the "veteran" of the staff (Harrell) has a career 4.81 ERA and 4.45 FIP (to go along with a WHIP of over 1.5), Folty and Wisler struggle to keep the ball in the park (for now), the pitch to contact guy in the group (Blair) is getting shelled in AAA, Newcomb, Sims, and Ellis have trouble throwing enough strikes to AA hitters.
The Braves don't come close to having 15 guys who are ready to be solid contributors at the MLB level, much less be considered "good" at that level.
I've got really high hopes too, but many others have pointed out before how dangerous it is to count on many of these guys reaching their ceilings - and they're right IMO. I'm sure someone can point us to a much better number, but if you simply use the rule of thumb that Duquette and Bowden have been referencing on XM from a GM's perspective that one in three of these guys have a shot at being "successful" (their opinions have been that at best one in every three will get hurt, one in every three will flame out as starters, and one will be "successful"), I can't fathom ANYONE can have a surplus (since I'd argue we've got better numbers than anyone else in the game). We've got lots of talent, but the chances of having them become my definition of "good" - #3 or better SPs - isn't great. We're still going to need to have a lot of things go right.