I see you’ve since closed the poll (after a couple minutes of me trying to figure out why I can’t vote lol) so if my opinion matters at all, I like the placement of them in 3 the best. And since I see you’re going for a “sitting on the floor” viewpoint, it wouldn’t take too much extra effort to find a floor background and put it at the bottom of the picture, right under the girls bums to give the appearance that they’re sitting on the ground.
You could also do that with 2, if you wished, since some of the wall is still visible under them, but obviously it’s up to you. Just my two cents 