Reduce Edges and Faces

I got a model sent to me by a colleague intenteded to use in unity and maya but the number of faces and edges is extremely big
(200.000 faces and 600.000 edges).
I ve tried Cleanup extension,Artisan poly Reduce and PolyReducer 0.1 but the number of edges in nested components doesnt reduce no matter what i try.I m a complete beginner in sketchup so any help would be much appreciated
Thank you

Those numbers aren’t too big, do you have a problem with navigation with this model already?

Yeah i have a problem in maya and unity too when i export the model.I want to reduce the polygons because its aimed for mobile vr use .If i try to reduce polygons via maya the model corrupts. I dont want it to be low polly but now its extremely heavy