Well, I do believe that the Garboid is just fine as a card. The Pest is fine as well.
Why you may ask? It has simple counters. Sanctuary? Completely nullifies the effect. They stole your sanctuary? Have more, or Enchant Artifact.
Otyughs also find them to be quite tasty.
Also, please change the topic name. It is Devourer/Pest, I thought you wanted to nerf TWO cards at first.