The Lions interior OL is definitely a mess, and that's assuming Miller can step in as a rookie and be solid.
It's why I'm skeptical of how good they'll be this year, the OL and running game has been the engine for their entire team when they were at their best and now the OL is pretty decimated, it's Sewell and a bunch of JAG's/young guys.
Montgomery is also gone as the hammer and their secondary is a complete mess as well.
People assume they're going to be good because of the big star names on offense and Hutchinson, but I could easily see them missing the playoffs again.