Entirely my opinion, but I believe that there are breakpoints at multiples of 1,2,5. So, changes in org structure are needed to adapt at 10,20,50 (and further at 100,200,500) counts. More formality, more processes, more tools, more variety of roles.

If someone is doing a task which takes 4 hours a week, in a team of 10, on scaling to 50 it likely becomes a half FTE level work. Not everything scales that way, obviously, but it's a good way to model new roles needed.