Transactions in sports (and other pursuits, I suppose) often come about because of the familiarity of relationships. Those relationships can create self-limiting options, but they ultimately come down to trust.
The Vikings have targeted (and sometimes landed) defensive players who had previously worked under Mike Zimmer. Part of the appeal of Nelson Cruz was how Twins GM Thad Levine saw first-hand the impact he had in Texas. There are countless examples of two teams that have made multiple trades with each other, buoyed by connections built over time.
New Timberwolves President Gersson Rosas surely has connections throughout the NBA.