We’ve chosen to go a similar route as with your option B for overhauling the retreat mechanics. If your men are already on the edges of the map, you’ll safely retreat as before. If they aren’t, they’ll now attempt to speedily move to the edges of the map by themselves until either they succeed or die. While this is going on, they’ll get a defense bonus for moving through zones of control, the amount of which scales with the chosen difficulty level. They can still fail at getting away, get shot in the process and whatnot, but there’s a reasonable chance that they succeed, so that retreating always remains an option.
The new mechanics speed up the process of safely retreating quite a bit if the enemy isn’t able to close the distance anyway, but it also means that you can’t just teleport everyone to safety anymore if you’re already engaged. The skill and equipment of your men, your positioning, and who you’re fighting against now all have an impact on your chances to retreat unscathed, and it’s no longer just random injuries for everyone.