We don't really know much about Bandle City or Mount Targon in terms of location.
Bilgewater is certainly to the East of Piltover, as seen on the official map, although where Shadow Isles is in relation to Bilgewater isn't well known. Olaf went to Bilgewater, so I'd expect Freljord and Bilgewater to be closer than depicted, so Noxus is probably smaller than presented. Noxus being bigger than Demacia is probably true, though. Demacia seems like a declining world power, whereas Noxus seems to be a still growing empire.
Zaun is just underneath Piltover, so it makes sense it's not visible on the map.