Forget why they're allies, if the Republic is as aggressive and hostile as I'm assuming from skimming, why the fuck does the Kingdom even have anything to do with them in the first place?
This arc is just raw stupidity conjured forth from the author's darkest bowels to try and desperately keep this story somehow going.
Thanks to DanMachi all brown skinned tribal-themed women are depicted as sex-starved super strong warriors. The kingdom wants them as allies to keep them from forming raiding parties to steal all the shotas.
Hope he domes her instead of coming to some sort of draw.
They've been pushing it hard on how everyone thinks he's just some weak inferior man for so long that it'd be super disappointing if he didn't body her then and there. Haru chad arc or simp arc? Guess we'll find out.