WfaS was basically a pay mod for very local area, I think Poland cuz it's about a polish war in 17th century or something, where taleworlds licensed the game out to local devs to create the content, and yes it was originally arranged before Warband. I think it was successful enough there that they basically decided to translate it to English and release it for rest of world as a quick cash grab (Paradox and Steam both hyped it as a new xpac when in reality it was inferior to Warband). It was a cheap move that might have burned some people (never bought it), I hope at least Taleworlds made some decent cash out of it.