Unreal diffrent Vertex Count

Hi all,

as you can see I imported diffrent cubes with diffrent hard/soft edges into Unreal and I am wondering about the Vertex count. The more smoothing groups I will use, the less vertex I get.

I use Unreal 4.4 Maya 2015 and FBX 2015 plugin. ( FBX smoothing groups, smooth mesh and triangulation is on)
Got the same results with smooting groups in 3DSMax 2014.

Does anyone else have this weird problem too?

Thanks,
Malte

I attatched the maya scene with its fbx files.
[maya file and fbx files][2]