What I would like to know, if anyone read it, would be which LB, Matthews or Barrington took over the Buck linebacker duty when Hawk left the starting lineup.

Hawk was essentially the strong LB, his job was to occupy the fifth lineman (usually a Guard in base). His declining size and strength made this very problematic last season. The other position (Barnett/Bishop/Jones) was Mack (weskit/pursuit).

If Matthews and Barrington stay starters, then you can draft for either.

If Matthews returns to OLB on early downs (unlikely unless they hit they jackpot) then you need Barrington's complement unless you think Thomas or Bradford will make it.