Yes...to ALL of this.
I obviously don't know exactly how the Brewers go about things, but I VERY much hope that not only do they have a very good..."apprentice," type program.
I fear a brain drain with Stearns. Not all the top dogs(though perhaps some).
But those scouts and Johnson, the pitching lab, Charlie Moore...so many guys behind the scenes that we hear or see VERY little about who churn out good relievers by unlocking a different sinker in the case of Peguero or they turn an awful defensive catcher into a guy ranked in the top 6 in throwing, blocking and framing as they did with Contreras.
But the to build the type of system we have now, it requires not just a big investment from ownership in the department(Which we've gotten) but as you said, those guys who go everywhere to uncover those arms, who develop relationships with the players, who gauge their demands so we can sign 18 guys in a draft class MOST of us would have been THRILLED getting ~14 players signed in.
So I hope we keep Johnson obviously, but it runs so much deeper than that. From top to bottom, we've never been run this well IMO(Stearns is also largely to thank for this) in the scouting department at all levels and we've never had a farm system that has Jackson Chourio and we're already looking at a 17 year old with a .300/450/550 slash line in the DSL who could VERY possibly become a top 100 himself next year and will likely/possibly start in full season ball next year before his 18th Birthday due to his advanced approach.
VERY exciting time to be a Brewers fan at all levels...though, think about how good we'd look if we could afford a 4th OFer or a middle reliever for ~8-10M a year and get rid of our Latin American department all together!