Ḥuwār and sadīf do not designate the same item. The first is the young camel being roasted; the second refers to pieces of fatty meat associated with the hump. Musarhad qualifies how that meat has been prepared or cut.
TermMeaning and role
حُوَارYoung camel; object of roasting
سَدِيفFatty pieces of hump meat
مُسَرْهَدDescribes the meat as cut or prepared