Think of the 3-4 scheme for example. Joey Porter, James Farrior, Bell, Harrison, and etc were all big linebackers. In a 3-4 scheme the nose guard is usually double teamed, and the ends are not like your typical Jason Taylor looking like ends. The defensive line acts like if they are blockers to the linebackers to create gaps. Either how, all of those linebackers are heavy, strong, and they can go toe to toe with tackles, guards etc. They also happen to be fast too , and be able to drop back in coverage. Since there are 4 linebackers, they can cover a bigger area of the field. Owusu would be too small for those schemes. Someone like Micah Parsons would be ideal for those schemes but they have no need for them as their linebackers are already one of the best groups in the nfl.