It looked to me like initially Guyton replaced Mayo as the green-dot guy and then they switched to Thomas. One of my things I noticed this off season was that a lot of people were looking at Crables leg mass, but Guyton seemed to bulk up well in his legs. Hes still not great at getting off blocks, but he plays a bit stonger
Ninkovich played a decent amount after Thomas moved inside, hes pretty good for his first couple months of learning the D, I just dont think he has amazing athletic ability.
Maybe BB just puts
woods-guyton-thomas-ninkovich/banta-cain in the 3-4 and
woods guyton-thomas in the 4-3,
and doesnt pick another LB