At least last year (Facebook
Q&A session), ground units were planned. I don't recall seeing any updates on that in the info released recently around E3.
I don't know if you can build anything from the strategic map before combat. I'm not sure there is enough room in each region to show much in the way of building facilities for research and development, etc. Managing regions may be done by talking to advisers, or something, with the world map focused on combat strategy.
Welcome to the forum.