Jones lost his starting job because of lack of discipline on the outside, his inability to get off blockers & hold the point of attack, and lack of pressure. Not only has he shown his arsenal is limited in pass rush at this level but he is a liability in rush defense when they run at him. He looks like a fish out of water in coverage too. Taking the pass rush out of the equation...None of his deficiencies translate well to the inside. To be honest, Williams would outplay him there. He needs "seasoning" and that will come with his reps logged in situational football & rotation. He will benefit from watching & another off season in an NFL program. His upside is outside in a 3-4 but he has work to do.
Too early to give up on Mr. Jones, IMO. IIRC, James Harrison had to do a little work on his game before he became a productive OLB...but that turned out pretty well. No reason I can see that Jarvis can't do the same thing...but he has to want it bad enough.