The issue is that while there's no political advantage, the options really aren't balanced on the level of narrative cohesion. The big question in play is what the plan is for Gan Guangli's narrative?
The reason that's the big question in play is that, in this tournament, Gan Guangli is the only participant who has a narrative worth mentioning. Everybody else we care about is practically guaranteed to pass into the inner sect. Gan Guangli has higher requirements to remain a retainer of Cai Renxiang. He basically has to make it to the final 2. But even more importantly than that, Gan Guangli has an answer to give.
Last year he lost at the preliminary stage, and it kicked off questions about what being a Soldier means to him, and how he'll engage with that ideal while fulfilling his duties as Renxiang's right hand man, as her general. This round of the preliminaries is a narrative mirror to last year's, and it's the best opportunity to showcase his answer to that question. Which is extremely important, because it's core to not just his personal characterization, but his trajectory within the organization of Renxiang's inner circle and the upcoming diplomatic project.
Like or dislike him, this scene is vital to Gan Guangli's existence in the narrative in a way that this opportunity simply isn't to Xiao Fen's. If he doesn't get this scene, it's going to be extremely difficult to write his presence in the narrative fabric in a way that isn't deadweight dragging it down. There's a missing foundation to serious characterization of the guy, and this exact opportunity is essentially tailor-suited to lifting the fog clouding his personal and philosophical redemption. Essentially, we need to know Guangli's answer to the questions raised by his previous loss before anything can be done with his character. And simply winning the tournament, a scene we're no doubt locked in to watching, doesn't answer that question.
Gan Guangli deserves to stand tall and shine brightly in the power of his ideology. This is that stage; it's the only one that can serve as the first, but it will be the first of many.
[X] Gan Guangli, your ally and fellow retainer, you could talk him up a bit, and spin your looking away from Xiao Fen as having no doubts a Bai will pass the preliminary.