IMO go for it. Sounds like a very plausible and interesting bit to your character's backstory. Unique dialects form all over the place, even when people are mixing, so a reclusive Seeker tribe developing their own is perfectly within reason.
"Song dogs barking at the break of dawn, lightning pushes the edges of a thunderstorm; and these streets, quiet as a sleeping army, send their battered dreams to heaven."
Hipparion Tribe (Sagolii)Â - Â Antimony Jhanhi's Wiki