As a Reincarnated Aristocrat, I'll Use My Appraisal Skill to Rise in the World 8 (manga) by Natsumi Inoue

It's brains over brawn in this new isekai adventure! One day when leaving work, a salaryman dies and is reborn in another world as the weak child of the noble Louvent family. Using his "appraisal" skill, which lets him see the stats of others, young Ars Louvent recruits the best people to his side in order to turn his country around.

TAKING THE FIELD.

Thanks to Licia’s skillful maneuvering, Ars and his followers have succeeded in winning Paradille to their cause. This diplomatic victory puts them on even footing with Prince Vasmarque and his new ally, the duchy of Seitz. As Ars comes home in triumph, Prince Couran gives him a new mission: leading Missian’s forces in an assault against Arphada. Shaken but resolved, Ars prepares to make his debut on the battlefield.