Alma 18:16 specifies that the six slingshot victims were actually killed; Ammon’s killing the leader with his sword makes a total of seven dead. Ammon may have held the leader responsible for the acts of disruption and attack and, hence, intentionally executed him. The amputees were severely injured, but probably they could recover. Mesoamericans were well used to battle injuries and were doubtless capable of arresting the blood loss.
Variant: The phrase “with his sword” was not in the printer’s manuscript or the 1830 edition. Undoubtedly, the phrase was added to clarify what seems to be a conflict between the deaths of the original six and the leader. Without the added phrase, it would have read “slew none save it were their leader,” which contradicts the death of the earlier six. The additional phrase removes any ambiguity.