I know he's a ways away, but Anderson has been pretty dominant, aside from just the basic 'all pitching prospects have risk' I don't see why you think he's a 4/5 type.
Newcomb isn't going to be a bullpen guy, some team is going to let him start. Honestly with his build, high-end stuff and ability to strike people out - I don't think its tough to see him at least becoming a back-end inconsistent type starter. But I'd be very surprised by a move to the pen with him. He'll start somewhere, the biggest question with Nuke is how close to his ceiling does he get.
The Braves currently have 6 pitchers that could be considered Top 50-100 prospects (and none in the elite and more "sure thing" Top 10). Historically, about 40%-70% of those guys fail to produce even 3 WAR at the MLB level.
I am projecting 1 to have a significant career, 2 to have decent careers, and 3 more to have some sort of MLB career in the BP.
If anything, I am being optimistic about this group of pitchers.
I realize Braves homers think all these pitching prospects will pan out, but facts are facts, and the facts are that it's more likely each one of these guys produce nothing than produce significant careers.