When you trade a 4th round pick for a QB who was a top three selection that’s going to send a message to your starter. With Dak up for an extension soon, the Cowboys needed another option just in case he continued to regress. I’m sure the signing of Lance spurred Dak on some. However, the biggest reason he’s playing so well is the new offense and change in OC. A lot of changes were made during the off-season to help Dak and so far they’ve worked.