Yes, as per the article, other teams got great use out of your first round picks. Ware was a huge part of that Denver super bowl team, and Newman had a career resurrection in Cincinnati.
Newman had a much better DC and surrounding players. Yes he looked good in Cincinnati, as well, he followed Zimmer to Minnesota and did ok there.
Ware, the same thing in Denver, he had Von Miller there too. He was a big contributor though, and he did play well in the SB. His last few years in Dallas he was battling injuries and a bad DC. That and his cap hit played a huge role in releasing him. Can't fault Dallas at the time for either player, as Newman was having injuries as well.
Hitchens, they wanted to keep him, but KC offered too much. He was no better in KC, but played well with a supporting cast. Though their defense at times seemed not so good, they played big when they needed to. Something the Dallas defense has not done for years.
Bennett to Bear played decent, but not great, nor did he play great in NE, he did drop the potential game winning TD in OT against the Falcons, but the next play or 2 someone else caught it.
So yes Newman and Ware played well. All other players that left Dallas never really contributed as to being a huge factor. Unless you count Amedola, from years ago, that would not have cracked the 53 at the time. Not any fault to the team. A hindsight TC cut many used against the FO no matter what. Things just happen at times.