Agreed. On this earth the deserts are located on the Tropics of Cancer and Capricorn, for the most part (not sure about the Gobi) and the actual tropical climates are on the equator. So I always think of general climate bands as a color gradient going from white to brownish-gray to green to tan to dark green (over-simplified, of course). So I always chuckle when I see deserts on fantasy maps placed all willy-nilly. It might make for a good story and all but the physics of climatology doesn't really support willy-nilly placement...there are reasons for why deserts are where they are (temperature, wind, jet stream, rain shadow, ocean currents, precipitation and evaporation, above or below sea-level, etc).