What position did Bruce Smith primarily play?

What position did Joe Greene primarily play? Joe Greene is best known for playing with which NFL team? Which college was Joe Greene playing for when he entered the NFL? What jersey number did Joe Greene wear with the Steelers? Bruce Smith is best known for playing with which NFL team? Which college was Bruce Smith playing for when he entered the NFL? What jersey number did Bruce Smith wear with the Bills? What position did Derrick Thomas primarily play?