Al Davis definitely loves his players to have a certain look, often called a "get off the bus" look about them. Height/weight/speed ratio freaks are often tied to Al Davis, but year after year it seems like the Vernon Gholston/Mike Mamula type workout freak who comes out of nowhere and becomes a top 10 pick because of hype and Al Davis stays away when given the chance.
This year it's Bruce Campbell because the guy has every measurable Al Davis typically looks for. Some years Al reaches and takes someone higher than they need to be drafted, but he typically avoids the workout warriors.
To get a better understand of previous workout warriors who should've been drafted by Al Davis based on the type of athlete they are, please check out the following slides.