Does anyone else think the three brothers in the finale are a weak part of Samurai Champloo?

Don’t get me wrong, I absolutely love this show. But rewatching the final three episodes (Evanescent Encounter Parts 1-3), I keep coming back to the same issue: Umanosuke, Denkibou, and Toube as the personal antagonists for Mugen just don’t feel earned.

They’re introduced in episodes 13/14 as government officials on a ship that Mugen and Mukuro raid. The explosion scars and deforms them, they swear revenge, and then they show up in the finale as these incredibly dangerous fighters capable of pushing Mugen to his absolute limits. But the timeline of the show doesn’t suggest much time has passed at all, so where did that level of skill come from?

Kariya Kagetoki works as a villain because he’s framed as a once-in-a-generation swordsman from the start. The brothers don’t get that same treatment. They just kind of arrive fully formed as elite threats with not much explanation beyond the explosion transforming Denkibou.

Jin also doesn’t really get a personal antagonist in the finale the way Mugen does, which feels like a missed opportunity given how much rich backstory he has.

Curious if others feel the same way or if there’s something I’m missing that makes the brothers work better than I’m giving them credit for.