I have all four (and more). I'm really liking the P365 as a newer CCW, but I would like mag compatibility between my duty and sub-compact pistols and the G17 and G26 meet that criteria. If you went with the P320 and their sub-compact size, it would be a little more comparable. I shoot them all well, but I've found the compact sizes (G19 and P320 Compact) better all-round size handguns.
Commonalty is good as you'll likely do more training with your full size (speaking of most classes), and for me, my CCW's just don't get the same amount of rounds through them. It's nice having similar platforms for consistency. Out of those four, I would probably choose the G17 and P365, knowing magazines are completely different. One carries better for me, and the other is a better duty gun for me.
ROCK6