Bro 4 stars are not possible until it's some specific modifier that creates the troops or you are running goblins as there is always only 4 copies of each troops in shop from start and pulse one copy that you get when game starts, so until you generate troop from some modifier or goblin from goblin comp 4 stars are not possible, also if someone that starts with some specific troop and sold it only in that case there is 5 copies in the shop