If the move makes sense at the time, which it did, then you regret nothing. You hope the player you got did the job you need and wish the other well. Pom solidifies the BOTR with the upside of a 2-3 for low $$ and years of control. I think it was all part of the 3-4 year window plan.
Espinoza has some special qualities, that if developed, he could become a very special MLB player in 3-5 years. As long as Pom does what was expected of him, then the deal should have zero regrets regardless of how Espi does in a few years.