Dylan Bundy was ranked as the second best prospect in baseball by BA while Kevin Gausman was ranked 26th. Manny Machado lost his eligibility and Jonathan Schoop did not appear. For the sake of this exercise, I am going to identify Machado as a top ten ranked position player on BA's list and Schoop in the 91-100 ranks on BA's list. I will also be using the probability figures determined by Scott McKinney in his post on prospects.
If we assume the following players are typical prospects for their groupings, we get the following table projecting future value (Bust < 1.5 annual WAR; Regular >1.5 annual WAR; All Star >2.5 annual WAR):
This then yields this next table:
Bust Regular All Star Dylan Bundy 1-10 Pi 59.2% 40.8% 26.5% Kevin Gausman 21-30 Pi 79.4% 20.6% 14.3% Manny Machado 1-10 Po 37.4% 62.7% 39.6% Jonathan Schoop 91-100 Po 66.7% 33.3% 14.3%
How consequential is it for these players to develop into star quality production?
Probability Four All Stars 0.2% Three All Stars 3.5% Two All Stars 19.7% One All Star 44.0% Zero All Stars 32.6%
Personally, I think at least two of these players need to become exceptional players for the team to remain relevant with respect to the playoffs. That puts the chances at 23.4% or approximately one in four.