Actually the original Sindhis are either the samath (kalhoras, mir Bahar, rajpers, pownher etc) or drawer Sindhis(bhel, kohli, etc). Others are again outsiders. Like laghari, bhutto, lashari, sial are siraiki people. Marre, jakhrani, zerdari, dahni, magsi all are Baloch tribes. Even soomras of Sindh are originally from haryana(originally jaat).
Edit: agha, durrani, pathan casts are all Pashtoons, not Sindhi. And I am not talking about Rizvi, Syeds, Shah's, makhdooms etc at the moment. Sindh is, and always was more multicultural than these ethnic leaders think it was. Current clash in Karachi is nothing but an oppressive move by one party over some marked members of same diverse society. It's an oppression nothing more, and state is not doing anything to save her own people.