so for some reason when i upgraded the armor i lost clearing % liek it went from 51% to 35% idk if its becuse theirs something to do with the armor being heavy or  not but i think it should haev improved chances

Clearing % = the preview is just a simplified number. It doesn't take in count all the combat calculations. It works only with hero count, equipped weapons, equipped defensive gear, and current health. So if your clearing % went from 51% to 35%, some of these aspects must have changed. .... in simple terms, it's just a preview number that doesn't affect the real combat.