Very simple but nice stalls! I actually like them a lot. If these were my stalls I'd be happy as long as I could have a small stable. I would probably do larger stalls but they could also look small from the angle the picture is at.
Round stable with horse boxes and a central storage and work room. Would allow large paddocks out of the stalls and still have central hub for barn activities. I would dub this barn "The horses of the round table/stable"
So this is an idea- instead of building a huge barn this carport (can get them really tall too*) and put my simple stalls in it (spray paint the wires though so it looks prettier); look into sand flooring