on one hand, the author does hype characters very frequently, more notably during this tournament.
on the other hand, Yujiro himself states that he never expected anyone to have a gun in the koruaken (forgive me if I miswrote that), which made him lower his guard and allowed the hunters to catch him by surprise.
Yujiro's performance on warzones were possible (at least in the story) because he was always on guard and expecting to come into contact with armed combatants.
Here, he was caught by surprise unlike in any other battlefield he's ever set foot on.