If your offensive line is good enough, you can generally survive having a weaker player at one spot. The Falcons in 2016 had a terrific group at four spots on the line and were able to get by with Chris Chester at right guard as a result, even though Chester was easily the weakest link for that particular line.
Chester had also been a full-time starter for eight years before 2016, including one year with Atlanta, and was a durable and proven player. The Falcons aren’t even close to having the luxury of having one of their guard spots go to someone like Chester, and thanks to an injury to veteran Josh Andrews, they won’t even have their presumed starter at left guard against the Eagles.