Well the Samma is a Baloch tribe settled in Balochistan and Sindh of today's Pakistan.
The current Chief Minister of Balouchistan Jam Yousuf comes from this family and as Omar al Hashim said they were completely muslims but still with their old names.
Tradition and Religion are two different things, I mean you have to implement and practice your religion beside not forgeting your tradition.
My own name is not a Islamic name while I am a Muslim but I have tradition of my own (which is older then the history of Islam).
So it's possible to keep your tradition in place while practing your religion, a good example of it could be the weddings in Pakistan.
They follow the entire Indian tradition + the Neka (rule of Islam), I guess it's a good thing that they still have their tradition with them while implementing Islamic rules.