I'd start all 3 of your current linebackers over Tulloch. I had Tulloch as a 2011 Bust/Overvalued player. He went from playing on a team in Tennessee that gave him TONS of tackle opportunity with little competition for tackles within the front seven to a team with less tackle opportunity and a lot of competition for tackles within the front seven (Levy, Durant, Suh, Avril, KVB). I never expected Tulloch to be anything more than a LB3 option. I would consider him a LB4+ moving forward. Dropping him will depend on who is available on your waiver wire, but I wouldn't hold my breath for him to help you out that much down the stretch.
Thanks guru. It's frustrating because I fell in love with last year's numbers when drafting this year. I've kept him rostered in hopes for a resurgence but much like you recommended have played my other LB's over him. I just added Hawthorne too (who I'm shocked was available). Talk about having opportunities. There's nobody stopping the ball carrier in front of this guy. Sadly, Tulloch might be my next guy dropped.