This is 100% wrong. You need to seek out some people with actual industrial mining experience if you want answers to these questions. Honestly a 100k build might net you 60 machines with power supplies if you went with new S9/T9s. You can run the entire business by yourself at that point. There is very little maintenance to do with such a small number of machines.

P.S. Someone mentioned R4's. Stay as far away from them as possible. The price per GH is higher than either the S9 or T9 as they are for the ultra foolish home miner that doesnt care about making a profit. Also a quick search of the hardware section will confirm they are extremely unreliable.