This article objectively shows which is the more efficient model:
http://www.fangraphs.com/blogs/valui...100-prospects/
The only reason folks argue for the "stockpile pitching" model despite all evidence that it is inferior is because the Braves are doing it, and they like to cheer for the Braves.
I am 100% confident that if Coppy had stated 3 years ago, "we think building around position prospects is the best way to build a long term winner because hitting prospects have proven to be more valuable over the last few decades", we wouldn't be having this debate.
We probably also wouldn't have seen 7 pitching prospects bust at the MLB level.