Note that the AfD could create a coalition government with BSW in Thuringia, but not Saxony.
BSW is a new party that splii off from Die Linke Which is the former Communist party. Them and AfD would be strange bedfellows and I doubt BSW would do it. No CDU will line up with a bunch of leftists or try to govern without a majority. AfF’s only way into political power is to win an outright majority.