Instanced static mesh just did not exist in older versions of the engine. It wasn't properly supported by hardware before DirectX 11. Even after implementation in DirectX some hardware still didn't support it. Many tutorials aren't a realistic representation of a actual game workflow. They show some of the techniques but…
sprunghunt said: As you say, there's no need to become obsessed with the optimization topic. It's good to work with common sense and keep in mind the technical capabilities of the final hardware the project is targeted for. The artist should take into account LODs, texture atlas, and conducting performance tests…
I understand that you are referring to the fact that the Instanced Static Mesh feature did not exist in versions prior to Unreal Engine 4, specifically UDK 3 and earlier. In UE4 version 4.10, it was already possible to manually instantiate one or several meshes, although this method might not have been well-known in 2015.…