Lawrence's deal is terrible for Dallas, and I have been a advocate of cutting him to save his salary in the past. But what the playoff game showed me is that this team cannot win with offense as long as Dak is the QB. I like Dak. He is a good guy and a good QB, but there is a problem that shows up in big games. I believe it is something that will never go away. So the answer is to build the defense, and the running game. They already overpaid Lawrence and Dak. It is too late to fix that. At this point they have to accept what they have and start focusing on how to get the most out of the players they have.
Gregory and Armstrong are free agents and the likelihood is they will not sign both of them. In fact, there is a good chance they will not be able to re-sign Gregory because he will get an offer he can't refuse ad the Cowboys can't match. It would not be a good idea to cut Lawrence if Gregory and Armstrong both leave. Having Golston and Basham as the only returning DEs would be a disaster.