I have seen multiple monitor ports work and not work on different latops. This is something that is entirely dependant on the particular implementation of the chipsets on a particular laptop. There is no rhyme or reason for this feature, so you need to get this information from either the supplier or Lenovo.
The Nvidia Quadro K2100M chipset does support up to 4 monitors.
With an ultradock, a maximum of 3 displays can be run simultaneously. (Page 107--labelled number--in the manual.) But there is no indication on whether the VGA and mDP/Thunderbolt ports can be used simultaneously on this model series in the manual.
Your best bet would be to contact the reseller and ask them, or get the exact model number and contact Lenovo direct. Lenovo's website is not clear, and Lenovo does not offer a document with the exact specifications and features. I checked Lenovo's sales and support sections.
My advice is: Do not buy Lenovo. They are a rubbish company to deal with, this being just one example.