I wouldn't do it, but if I did, I would consider keeping BJ and throwing back Prado. I think you should try to get the #7 pick and another and potentially pull the trigger. Having picks #5, #7, and another early round pick can make a huge difference in a keeper league where only 5 are kept.
I agree that you don't need to keep so many pitchers. You should see if anyone will bite on Dickey for a pick. You'll be able to get Prado back with those picks, you'd also be able to get Hamels back at pick 5.
A little of a trickey situation, but I'm all for gathering extra early draft picks.