The problem with waiting for prospects is that it doesn't necessarily mean being sustainably good long term, It might turn out that way if they all succeed at the ML level, but the chances of that happening are very low. Meanwhile, you've lost 2-3 years of winning baseball games while you wait for them to develop. The "reported " players available this year in trade or FA include Bieber, Naylor, Hoskins, Clase, Kim, etc. and any or all of them would make this team NL Central favorites for a sustainably good long term.