I think that's debatable. There was a lot of worry about Pomeranz ability to pitch down the stretch, and he's never proven to be a starting pitcher for a full season.
Surely most are happy with the Chris Sale trade, but what if we traded Moncada, Kopech, Basabe, and Diaz for Thornburg instead? I think it's reasonable that most sensible fans would see that as a major waste of resources.
I found the trade for a guy who's never proven to have the durability to be a starter in the majors a major overpay by giving up a guy who's arguably the best pitching prospect we've had in a decade, and arguably the best pitching prospect in the game. Now Pom may very well come back and prove himself and I'm optimistic he can but I don't like the trade and I suspect I will never like a trade on that scale. If I'm giving up talent where the sky is the limit, I expect similar value back. I'd feel much better about packaging Espinoza up with a few other prospect for a more reliable and proven commodity E.G. The Sale trade.