David Laurila interviewed Brewers' farm director Reid Nichols for Baseball Prospectus and, happily for all you non-subscribers, it's a free article. Most of the interview can be paraphrased thusly:
Laurila: Which of these two approaches do you use?
Nichols: Some of both
That is to say, you could probably have guessed most of his answers, and Nichols is careful to say nothing overly bold. Still, there is some welcome illumination on how the minor league system is run:
RN: We have a manual that we've put together that our roving instructors help us implement. It covers everything, from how we run the bases, how we pitch, how we position our fielders, how we approach hitting, and the plays we run. We want to make sure we're speaking the same language, starting from the major league team and working down.
...
DL: How much does the organization monitor offseason programs?
RN: We have a conditioning manual that players should be following each day, and our trainers will call to check in for updates during the off season. We also encourage our players to spend their winters at our facility in Arizona. We actually implemented a program this year where we gave scholarships to twelve players to come here to work out.