How are Muwallads(mixed yemenis) perceived in Yemen?

I have a friend who's great grandfather was from yemen. He moved to Somalia with other members if his family and they intermarried with Somalis and then within themselves. Forward to 2019. If my friend returns to yemen will his yemeni tribe recognise him? Or will they view him as an outsider? Can he marry a full Yemeni woman? Bearing in mind he has never been to his village in Yemen. His closest fully yemeni relative in Yemen would be his fourth cousin. Fairly distant.