He typically only plays one side of the field, regardless of who is lined up. Only real exception was the first niner game this year when Crabtree and Browner were out.
Then they had him shadow Boldin.
Defense has been money. No reason to change what got you there.
D. Thomas usually plays on the same side as Sherman. If Denver feels the need to move him into the slot or the other side, then Seattle gains a mental advantage immediately. The motto of this defense has been "you have to deal with us."