It definitely hurts, and they're not just going down to their backups but also their backups' backups in some cases.
Gripes with mismanagement of LT aside, if they can somehow manage to get their guys healthy again and spending some time together, they may achieve "average".
I know that many of us have pushed to put Onwenu back at RG (including me) but I don't think they have the quality tackle depth to do that, and I also think that some of his struggles recently have been due to trying to make up for Robinson's poor pass blocking next to him. If they get both Sow and Strange back healthy, and one of them can go to RG, then I believe that would stabilize things a lot. Getting a higher quality player like Strange next to Lowe may help him too (though Jordan has done an admirable job).
Top line: Lowe / Strange / Andrews / Sow / Onwenu
Tackle backups: Wallace, Jacobs, Jones (PS)
Guard backups: Robinson, Jordan, Thomas, Leverett
Center backups: Leverett, Hudson (PS)