I just leave enemies lying where they were shot.
How cruel
Well, so do I haha, but for me it's common because I like to use the strategy of camping the choke points. Either with firearms or melee weapons. I don't usually waste TUs moving the bodies unless it's important for their survival, because every TU matters, but they still often end up on top of one another. It's interesting to hear that you haven't used such a strategy, but please don't let your personal bias disreagard other player's playstyle preferences.
logically there should be barely enough space for one or maybe two unconscious/dead units there as well
If it wasn't possible to have more than one body on a single tile, then we wouldn't be having this conversation now, would we?
so if you wanted to heal the bottom one, you'd need to push the top one away
Alas, the game logic tells us that each tile has infinite amout of space and that bodies and items have no volume.
Anyway, if we have a hundred different items on a tile, we're able to precisely pick out the item that we want, without needing to carry it to a different tile first.
The point is, it's logically inconsistent that we're able to choose which body we want to carry, but not choose which body we want to use a medikit on. And I'd love it if you could help me here~
Well, you can make the body in the medic's hands the priority target for the first aid kit.
That would be a step in the right direction, however it wouldn't be a good solution to the problem. You'd still need to spend TU picking up the body, but now you'd need both hands free. Freeing up both hands would take more TU than it would take to use one hand to relocate the body.