This thread is rediculous. The Patirots OL was the league's best last year, hands down. They got beat once out of 19 games. Find me another offensive line in the NFL that was this consistent, week in and week out.
Part of the reason this line has been so good is that, excepting injury, the same 5 guys have played together for 3 seasons. Offensive lines are as much about chemistry, continuity and teamwork as they are about raw talent. Messing with this line will possibly make it worse, even if we bring in a presumably more talented player.
The depth at RT is fine. O'Callaghan and Britt could make it as starters on more than a few teams in this league. Kaczur would start on at least half. My worry is interior depth, but it will take a little time to see if Welbourn can solve that problem. The problem is, anyone the team brings in is going to need a few weeks to fit into the system to prove whether or not they can earn their keep.