1UPT with non-military units

[ViterboKnight]

I've read Tom Chick's review, and I agree on him about the need to enhance the 1UPT (one unit per tile) mechanic of Civ6.
Most of the problems are around non-military units: settlers, builders, great persons, missionaries, apostoles, spies.
I suggest two changes to the game mechanic:

1. non-military units are NOT affected by 1UTP. You can stack them as you like.
2. non-military units can occupy the same tile of other non-military units of another civilization (or city state) you are not at war against.