Help with my linemen, please.

I have JJ Watt accompanied by Cameron Heyward and Lamarr Houston. Houston is going to be benched until he demonstrates something. Heyward is uninspiring. I have enough salary cap to play the DL of the week for a little while.

I'm looking at grabbing Charles Johnson (who is listed higher for the rest of the way than available recommendations Gilberry, Gholston, Liuget, Hankins, Spencer, and Robison), but I'm wondering if Frostee Rucker is worth a short term add instead. Thoughts? Thanks in advance, all!