Seekers aren't always referred to by their tribe names, and can be dropped in regular conversation. There are times when Y'shtola is referred to as Shtola, and F'lhaminn is referred to as Lhaminn. I could see this character dropping their letter if they were exiled or left of their own dislike, but if you want a reason for them to keep it, you could. I imagine they could also have been _'koga before leaving their tribe, if you were attached to using that name.
