They can be if the staff focuses on it.
The Butch years had a lot of speed.
At the WR position, Moss had a 4.31, Daryl Jones was a 4.3 or 4.4 and Andre Johnson was a 4.4 something.
Many of our RBs during that time were burners - Edge, Portis, McGahee. Davenport could move, but lost some...