Internal users will require a CAL which is about $100 per user. A forecast of the number of users will be used for Capacity planning for your SharePoint farm. Each server will require a server license. So the number of users may increase the cost of the server licensing.
Another example of convergent evolution is the overall body structure of the shark and the dolphin. A shark is a fish and a dolphin is a mammal. However, their body shape and how they move through the ocean is very similar.
Legless lizards such as Pygopodidae are snake-like lizards that are much like true snakes. Anolis lizards, with populations on isolated islands, are one of the best examples of both adaptive radiation and convergent evolution. Tuataras resemble lizards but in fact are in an order of their own, the Rhynchocephalia.