It's a BL Novel, where I think there was a tag Love Interest Falls First. There's an arc where the MC is a lame guy in a historical setting and the ML is the third prince, MC is the servant to the second prince but later recedes to the third prince because according to the story he (MC) will be discarded by the second prince. The ML also will force him of his will. I think he needs to improve the lives of the female protagonists to gain points, I'm not sure. It's been so long since the last time I read it so...
Arc 3 of There Will Always Be Protagonists With Delusions of Starting a Harem. The chapter starts off concluding the previous arc before starting the arc 3 EDIT: I just re-read the Request description, and realized i mixed up the character info of the MC and ML. Arc 2 of Perfect Destiny, MC is in a wheelchair and is a military advisor, ML is the 3rd prince.