Landscape Model Import

Hello! I am trying to build a low-poly landscape approximately 2km by 2km. I’ve messed around with the landscape tool/blueprint to flatten normals, but the look is not exactly what i’m after. I can easily model the landscape in my 3D software, but i’ve found old forum threads about how importing 3D models (besides a simple plane) as landscapes will not work, and how you must use the native landscape system. Is there any truth to that? For reference, here is the look i’m going for:

If it is possible to import a model like the image above as an fbx and use as landscape, how would i go about doing that? simply swap the landscape static mesh?

delete the landscape because you wont need it anymore. then import the static mesh, scale it to size and set the collision.