BS”D
Shneur usually is Shneur Zalman, not uncommon at all.
In EY my many friends who are named for the Alter Rebbe (Baal haTanya) or for grandparents who were in turn named for him call themselves Shneur because of a silly and vulgar tzioinish children’s rhyme which mocks the name Zalman (used as a symbol for those who are steadfast to masores avois and don’t change their names or way of dress).
Their US counterparts go by Zalman which is also the favored daily version of the name in this part of the world.
As for Yekusiel, one of the Satmar Admou”rim is named Yekusiel Yehuda but is called Zalman Leib. This is not uncommon at all as he and others who carry this dual name are named for an ancestor of Reb Yoilish ZYA. I see the connection between Yehuda and Leib, but Zalman is probably from Spanish Salomon = Shlomo and I can’t see the connection between Yekusiel and Zalman unless perhaps the name Yekusiel refers to Shlomo haMelech in medrash.