Demski replaces JFG. Nik has 33 for 326 and 3 tds which is a 66 reception, 652 yards, 6td pass which is better than what JFG did last year and is better than anything JFG or Kolhert did in Winnipeg.
Ryan Smith played 11 games for Winnipeg and had 53 catches for 488 yards and a td. Thompkins has 11 receptions for 180 yards and no TDs in 3 games. His current pace taken over 11 games would be 40 receptions for 660 yards. Case can be made that he's been more productive than Smith.
Now could we use more depth so we don't have to depend on Lankford or even Dressler given his age and injury status, sure but the guys you mentioned aren't better than the players who replaced them.