Taking a panorama made of subexposures stacked in each panel plus a separate untracked landscape set is daunting processing.
I managed to make it work but it wasn't easy. There is a nice program for Macs to do this heavy lifting but no Windows version.
I used a Sony A7r2 with an Irix 15mm F2.4 lens on a Polarie Tracker and a Panoramic head. The separate set of landscape shots were 181 secs each ISO3200 F2.4 (4 panels) The sky was 4 panels. Lightroom, Pixinsight, Photoshop PT Gui.
http://www.pbase.com/gregbradley/image/166294935/large
Greg.