Not just stances. Footwork, body movement, heck, massive parts of the entire system are dramatically affected by the physical environment in which a martial art developed.
Soft leather footwear of a Longhunter worn on muddy or dry, leafy, or gravely ground as he's fighting with a BP rifle, tomahawk, and longknife, yield vastly different movement, body positioning, footwork, and a fighting style from that of a duelist fighting a single opponent with a dueling saber, wearing hard soled leather shoes, in a salle. Civilian knife fighting systems of 1400 Germany tended to favor long, straight bladed, pointed knives partly because Europe was in the middle of "The Little Ice Age" and people were wearing more cloths. Conversely, civilian knife fighting systems in the tropical Philippines during 1800 embraced shorter slashing weapons to a much greater degree.
If you really want to learn how to fight in the system you're learning, train in the clothing they wore and on the terrain they fought on. At the very least, try to wear the same footwear.
If you want to train for "self defense in the street" you'd better spend at least
some time training in street cloths. Training "in the street" some might not be a bad idea either.
Peace favor your sword,
Kirk