Great post! These screenshots have a wealth of information in them. Not knowing anything about PIVX, the pics from git also tell me the following things:
1. PIVX is a fork of Dash.
2. Since the fork, Dash has been a lot more active than PIVX (600 commits vs. 3444). But 600 commits is still pretty active, so your point stands. I'm guessing it's just that Dash has a larger dev team. 
3.  The dip in activity around the beginning of 2016 tells me this must have been when it forked, so PIVX has been around about a year and a half, but has all the history of Dash prior to that. A pretty good pedigree.
4. Kore either never was really a thing, or they took their repo private shortly after starting. Doesn't necessarily mean they're shady, but open is always better. Between the two, PIVX seems more solid, at least until Kore releases something.