Yes I am sure you are thinking they would never work, they are too small and weak to be effective.
You are right, but there is an easy solution.
You make Compys a SWARM dino. When you evolve them it is a SWARM of four or five Compys whose stats as a whole are competitive. I would make them fast high health since in theory and enemy attack could only kill one or two at a time, and as a unique ability make them immune to being crited.