Community Discussion: Quantity or Quality?

This question was raised in the AQA yesterday. Someone asked me if I would prefer to have the Seattle Mariners Trio of pitching prospects (Taijuan Walker, A-; Danny Hultzen, A-: James Paxton, strong B+) or the Oakland Athletics Quartet of pitching prospects (Jarrod Parker, A-; A.J. Cole, B+; Sonny Gray, strong B, Brad Peacock, strong B).

I said I wasn't sure, given the attrition rate of pitching prospects, quantity had a quality of its own. What do you guys think? Which group of pitching prospects would you rather have?