That’s strange, I always had the option “Smoothing Groups” enabled in my FBX exporter. I can guarantee that my meshes are fine under Maya. I’m also not the only one that get this problem. (Also I don’t import meshes in Maya, I create them from scratch in Maya and export them as FBX file.)
My export options are : Smoothing groups enabled, Split per-vertex normals disabled, Tangents and Binormals Enabled, Triangulate enabled.
I have tested it again and I get a wrong polycount. If the fault is on my side I apology, but I checked again and again, something is probably missing in your explanation I guess.