Companion special stat doesn't count benefits from legendary armors and cloth (if can be equipped at the same time) correctly. For example, fortifying armors and grognak costume. If a companion equips fortifying armors first and then the grognak costume, the special system works correctly. If a companion equips grognak costume first and then the fortifying armors, he/she would only gain benefits from the armors and leave the +2 strength from grognak costume missing.