Both Marwat and Niazi tribes are major branches of lohani pashtuns, there actual origin lies in Katawaz Paktika province of afghanistan and they definitely also look like people from paktika afghanistan despite the fact that they have left paktika some 500 years ago and settled in Lakki marwat and mianwali respectively. Also Sindhi lohanas were assimilated among afghan pashtun at the time of Muhammad bin qasim invasion of sindh that is a long long ago , some 1300 years ago. Since then they have heavily mixed with ghilzai pashtun tribes of paktika such as Sulemankhel and kharoti etc. I think they are genetically same as any ghilzai afghan from paktika. That is also the reason why they retain afghan pashtun look because they were large tribes and were mostly endogamous during the last 500 years sojourn in lakki marwat and mianwali respectively.
Salim saifullah (marwat from lakki marwat)
Imran khan (niazi from mianwali)
So this proves real pashtuns look like pashtuns even after 500 years of migration.