premise: They all took the surname Singh, meaning  Lion  (all Sikhs are named Singh, but not all Singhs are Sikhs), and wore a turban and kept the five K' kesha (uncut hair and beard), kanga (comb for their hair), kara (steel bracelet), kachha (soldier's shorts), and kirpan (dagger).
hypothesis: Soldier's shorts and a dagger was not worn by any of them.