He could also take Overeem down, Bigfoot's a huge and strong guy.
Listen, Overeem is the rightful favorite here, and I expect him to finish Bigfoot within 1 round. However, NOBODY in the world outside of maybe Werdum wants Silva on top of them. That man's top control and GPN are brutal.
If he, for whatever reason ends up on top of Reem, then he'll have a solid chance of breaking him. Reem will have to be careful in this fight.