It's early yet but i'm currently favoring moving Corbett over to Center from LG, this would solve many problems in-house imo. I also have Trewyn as first reserve while Allen & Shelton hit the practice squad. My mock has us taking Cesar Ruiz in the later rounds for increased C/OG competition, although doubt he or any other center draftee will be considered as starting material for McVay/Kromer as a rookie. The starting & reserve OG positions could then be a fight between Edwards, Brewer, Evans, Trewyn, Corbett & a potential 2020 draftee. Obviously, a free agent Center or OG changes the entire outlook.
I realize it goes against all logic at this point, but don't rule out Demby yet in some role as the brass must still see something in him or he'd be on the practice squad instead of the 53, many of these players should show a good deal of improvement between their year 1 and 2 development. jmo.