He's captured during the Bragollach, so we may want to work it out soon.I don't know how we'll deal with the two Gelmirs yet, as we haven't really gotten to them.
I'd vote for renaming Gwindor's brother. Gelmir and Arminas have fairly significant roles in 2 different stories, even if it will only account to two episodes, total; while Gwindor's brother is simply there to be captured and later slaughtered. And since he will be captured this season, we won't have much time to build him up before then.I think the best way to handle the two Gelmirs would be to rename one of them. This raises the question: which Gelmir will actually be called Gelmir - Gwindor's brother or Arminas's friend?