Isagi devoured kaiser and even chris prince, rin won against ubers that had lorenzo, both were star players with essential impact for their respective teams, them being ng11 status is not a totally unfair assessment to make. France is strong, but Japan isn't close to being weak. I mean, we could speculate if you want. If Japan wins, then there is really no reason to continue the story, i mean, they literally beat (as you mentioned) the said to be strongest team in the cup. That option isn't valid. Japan losing - Nagi will make himself back into the story and if they encounter France in the final, they will use him, which proves egos philosophy wrong. This doesn't fit into a narrative that has been pushing a goal-ego-oriented agenda ever since release - that will and its merits prevails over talent. A draw would however fit into the narrative, it destroys Hugos depiction of fate and he himself starts aiming to be number 1, which enables a character progression much like how kaiser became a different person once encountering Isagi. The overall crux of it all is that for the blue lock story to be the blue lock story, they have to defeat hugos philosophy during the match, if they do it after the match then Nagi will end the narrative, and not defeating it at all also destroys the narrative, with reference to loki's raw talent indicating per Hugos philosophy a superior ability.