It's no secret that the Achilles' heel for the Dallas Cowboys over the past several seasons has been the neglect to improve things on the defensive side of the ball. Unfortunately, even though they devoted most of their draft resources to improve things, the Cowboys defensive performance so far in 2017 has been pretty abysmal, especially the run defense. But, I think the Cowboys run defense could improve if they signed veteran defensive tackle Arthur Jones.
Fortunately, the Dallas Cowboys currently have an open roster spot because of the decision of Stephen Paea to retire due to reoccurring knee problems. Paea was one of the few Cowboys free-agent signings during the off-season, and he was expected to come in and add depth to the middle of the defensive line. Unfortunately now there is a need at the 1-tech and I believe Arthur Jones could possibly be the solution.
In case you are unfamiliar with Arthur Jones, he is the older brother of UFC fighter Jon Jones and current Arizona Cardinal OLB/DE Chandler Jones. Arthur probably doesn't have the same kind of name recognition as his brothers, but I believe he can help the Dallas Cowboys nonetheless.

Arthur Jones would provide the beef in the middle of the Cowboys defense that they are currently lacking. At 6'3″, 320, Jones would be the biggest 1-tech the Cowboys DL have had in some time. But, he is a free agent for a reason.
Unfortunatelly, injuries and a suspension for PED's ended up cutting his time with the Indianapolis Colts short. He never really lived up to the contract he signed with the Colts in 2014, and as a result ended up on the street.
Now, I know what you're probably thinking. Why would the Dallas Cowboys want to sign a player who is currently on the street? Well, let me enlighten you.
Arthur Jones is currently the best option available to step in and help the Dallas Cowboys run defense at the 1-tech. I know there is a belief that the Cowboys will sign either Richard Ash or Lewis Neal from the practice squad for depth purposes, but Jones is better than both.

If Arthur Jones is indeed healthy, we could see the player that helped a dominant Baltimore Ravens defense win the Super Bowl a few seasons ago. Injuries unfortunately robbed him of his explosiveness during his time with Indianapolis, but if he is back to 100%, it's definitely an area of his game that would upgrade the Cowboys defensive line.
I honestly believe he fits the exact mold defensive coordinator Rod Marinelli looks for in his 1-tech. Jones is equally effective holding up in the run game or providing inside pressure to the QB. His last two seasons in Baltimore when he was healthy, Jones accumulated at least four QB sacks in back to back seasons. That is the type of player the Colts thought they were getting when they signed him as a free agent, but injuries never allowed that to happen.
Now, I have no way of knowing if the Dallas Cowboys have any interest in Arthur Jones, but to me it actually makes a lot of sense to see if he has anything left in the tank. I believe he could make an instant impact in the middle of the Cowboys defensive line.