Continuity is key
The overriding factor here. Heading into last season, the Bills had one returning offensive lineman, Dion Dawkins at left tackle. Across the rest of the board, there were wholesale changes. From left to right, the Bills offensive line primarily last season was Dawkins, Spain, Mitch Morse, Jon Feliciano, and Cody Ford. In keeping Spain, the Bills keep continuity. Buffalo keeps that trust and chemistry built their offensive line built amongst each other. In addition, quarterback Josh Allen also has the same chemistry built with these guys, so keep Spain can even help him in a way.
From 2018 to 2019, the Bills clearly improved across their offensive line. Were they prefect? Not a chance and the whole group can continue to improve, together. Bringing in new faces might not have completely derailed some improvement either, but at the end of the 2018 season, the Bills’ offensive line ranked No. 26 in PFF’s final rankings. Their most recent rankings? No. 21. Top-half consideration should be the goal for this group in 2020.