I am pretty sure they are all related but the Kadishevitz family of Anikst was very large with much duplication of given names. My wife's Grandma Finn' nee Kadishevitz 1st Cousin, Ida Tamara Kadishevitz married her 1st cousin who was known in Boston as Isaac Kadish (1878-1937). His Hebrew name was Yechezkel the son of Shimon. Ida's grandfather was Fayvish Kadishevitz, so presumably Isaac's was also Fayvish. My current thinking is that Fayvish was the son of Khatskel who appears to be the patriarch of a large number of the Kadishevitz clan and maybe the patriarch of them all.
Rabbi Kalman Kadeshevitz is believed to be the second cousin to my wife's grandma Finn nee Kadishevitz. Because of his position as the rabbi of Anikst, I am guessing that somewhere there is a definitive genealogy for him. I have not seen it but would love to.
Richard B. Brown