Re: Workstation?
Not been able to locate a Lenovo specification to clarify the situation, however, I did come across this article:
https://www.anandtech.com/show/12204/lenovos-thinkpad-t580-launched
It would seem to be correct the T580 doesn't come with a "a professional-grade GPU", instead the options are: NVIDIA’s GeForce MX150 GPU or Intel’s HD Graphics 620.
If you really need the Quadro then you need the P52 variant. Which given Lenovo are targetting the P-series at designers, engineers, and video artists ie. users of 3D modelling, CAD etc. and who want to use ISV-Certified applications (see https://support.lenovo.com/gb/en/solutions/ht101713 ), makes sense.
So suspect the "workstation end of the market" is a different workstation market to that being targetted by the P-series...