Is "Chút" and "Chít" synonym or are they one generation apart?

Wikipedia says that they are synonyms while Wikitionary says that Chút is Great-great-grandchildren and Chít is (Great)^3-Grandchildren while Wikipedia uses Chụt/Chuỵt for these meanings. There is a saying Cháu chắt chút chít, which kinda imply chút>chít. Also is Ông Cao, Ông Sơ and Cụ Kỵ just dialectal variations and is Ông Tổ anything higher than that or just one generation after that?