Maybe they will reappear later in the story with more relevance. Look at Bellamy and norland, even they resurfaced in the story to give their character more purpose or screen time. Bon clay and a bunch of other minor characters have had pretty huge roles. Maybe this is just a short intro for guys he plans to use later w/out having to display random abilities later.

I think this tourney arc is about to get wild. Half of the contestants are widely sought after criminals and warriors from countries the WG wants to put down. It would be insane if Green bull and fujitora make the largest bounty round up in marine history. That would make for an amazing milestone event in the OP world. It would give the marines back the bite they had before the WB war