No experience with the Lumix. The Olympus TGs are great cameras - I've owed 2 over the years. They are great for on the water shots and even underwater shots! Really apples to oranges to compare the Sony and Olympus - different tools.I like that D850! I've pondered going full frame for a long time. The D7500 is what got in the way of that. It's not your camera. The output is pretty good though. The fact that I own multiple DX series lenses ranging from 10mm to didn't help either.
I am familiar with the RX100 series (and BHPhoto) and owned one at some point. It somehow managed to disappear. I'm not sure what to say beyond that - except that I hope it turns up again at some point. It was a great little camera! That 200mm zoom on the newer version looks more interesting and more versatile for my purposes.
Do you have any experience with the Lumix ZS200? It has a Leica lens that goes from 24mm-360mm. Reviews on this camera seem good as well.