There isn't any reason to try to run down Schultz. He was a good, but not spectacular TE for the Cowboys for 3 of the 5 seasons he played in Dallas. He bet on himself by not signing the long-term deal the Cowboys offered him, and he ended up losing that bet when the Cowboys were able to replace him with another 4th round pick - Ferguson. Now, Ferguson is playing good, but not spectacular, for Houston. Good luck to him, and thanks for the time he spent in Dallas. No need to tear the man down.
Just be thankful that Ferguson is playing well. It will be interesting to see how Schoonmaker, who is bigger and faster than Ferguson, will develop. But Dallas got the better end of the deal because they don't have to pay Ferguson the millions that Schultz would have gotten - yet. And there is still potential upside for Ferguson to become even better.