Watkins allows Woods to play the role he was born to star in: The Isaac Bruce role of unstoppable #2 WR.
He will clear the seams for the TE's to run free down the middle.
Most importantly: No more 8 or 9 in the box for Gurley to bang his head up against.

I have heard the term "addition by subtraction" (GR) all month but this is a pure case of "addition by addition".

Kevin P.
Oh, and Watkins may improve Goff's game a little as well.