Why do Solar and planetary returns for locations in northern regions of world not divided same as natal charts?

The Solar Return should use the same style of houses as the natal chart so i don't think one should have oddly divided houses and one equal houses. It is just about the latitude and longitude at the time of the return. The only reason would be maybe the natal birth place was say North of the equator and the return place closer to the equator which i believe makes the houses more equally divided. Alternatively the software/website that did the return switched to an Equal House System from the return from say a Placidus one for the birth chart.