Reborn as Cannon Fodder in a Beloved-by-All Novel

This one needs its outline revised and the whole thing rewritten. Leaving it here for now; I'll come back to it later. Next book: "Book Transmigration: The Dragon-Pride Hero's First Wife" Cheng Meng transmigrated into the first wife of the male lead in a storybook she had read before she died. In the story, the male lead had women on both arms, while "Cheng Meng" bore his children and, with generous and virtuous understanding, used her dowry to set him up with concubines and beauties. Heh. As the bravest general in a matriarchal kingdom, even if she was in a storybook, she was going to marry a pretty wife! Cheng Meng looked at the "rugged man" male lead with disdain. He was a complete assault on her aesthetic sensibilities. Weren't soft, fair-skinned young beauties much better? The matriarchal kingdom went to war with a patriarchal kingdom, and Cheng Meng, its commander-in-chief, was written into a storybook by the enemy as a deliberate humiliation. Unexpectedly, after her death, this became her one chance at survival. So what if she was living in a storybook? Cheng Meng, who had spent every day teetering on the edge of death, was perfectly happy to live to a ripe old age in the storybook and marry another sweet young beauty! The male lead's perspective: What? His older sister, cousin, younger cousin, and fiancee were all in the dragon-pride male lead's harem? After transmigrating into a male-lead-focused novel, Gu Baichuan somehow became the youngest son of a doomed prince! Thinking about his fate, the original character was beaten to death in the street after his whole family was demoted to commoners, when he harassed his fiancee, who had already become the male lead's concubine... Heh. Dying was out of the question. But every named woman in the book was part of the male lead's harem. Was he really going to be single in both his lives? Gu Baichuan wept tears of sorrow. Gu Baichuan had read a novel while confined to his sickbed. Its male lead was a dragon-pride character with a "Literary Master System" who, with the System's help, became a celebrated, charming man of letters admired by countless women. The supporting character who shared Gu Baichuan's name was terribly unlucky. Every woman around him, without exception, ended up in the male lead's harem, including his fiancee. The male lead even held a grudge against him, and he died a horrible death beneath a rain of cudgels. When Gu Baichuan opened his eyes again, he had become that doomed supporting character. To secure a happy ending for his family, he had no choice but to make his move before the male lead could! But this beautiful older sister from the matriarchal kingdom is so pretty. He's just a shut-in, and he can't handle this!!! Big sis, look at me!!! P.S. The storybook the heroine reads doesn't show the dragon-pride male lead's golden finger. Theme: Live toward the sun and be a good person.