I've seen this pattern with growing teams within large companies. I believe there is some research on the phenomenon in the software engineering / project management literature that suggests the rapid decrease in communication efficiency as team size increases beyond a fairly small number of individuals is the root cause of the problem. Companies or teams that grow slowly can sometimes adopt new methods to efficiently coordinate larger and larger groups so that total productivity continues to increase even as average productivity per individual declines but an all too common failure pattern is that total productivity actually declines as the team or company grows.