Running 200 servers will force you to automate everything and also handle (relatively) rare edge cases, meaning added complexity, huge up front dev costs, and a

Running 200 servers will force you to automate everything and also handle (relatively) rare edge cases, meaning added complexity, huge up front dev costs, and a continuous dev effort just to stay afloat. Work has to be balanced in a clever way, making tradeoffs that you otherwise wouldn't need to make. The mental model shifts from individual servers to a whole ecosystem that shows emergent behavior (= things break in a totally new way). Maybe some of that also applies to 4 servers, but to a way lesser extent.