Lily Koku Kishidan to Cinderella no Yumine: Kiraboshi no Kakugo

For 300 years, knights have formed units and competed by shattering the life stones attached to each other's helmets—combat competitions have replaced war as the destiny of nations. Born in a village that produced many excellent knights, Nina, who couldn't handle a sword like the girls around her, had been ridiculed as a "failure." However, Licht, who saw Nina participate in a regional competition, discovered her talent with a bow and invited her to join the Knights' Order...!? (Source: Shueisha, translated)