Help! My Rough-and-Ready Live-In Son-in-Law Is Actually a Villain?

[A heroine who builds a fortune and becomes a business tycoon vs. a hero who is really a young general in disguise as a rough village man] [Transmigrate into a book / Married first, fall in love later / Secret identities] Jiang Heng, a wealthy heiress with dual doctorates in finance and mechanical engineering, transmigrates into a book as the merchant widow who dies young, the wife of the story's male lead, a top-scoring scholar. According to the original plot, only after she dies does the male lead marry her in accordance with their betrothal, take over her family's fortune, and help care for her younger siblings. After placing first in the imperial exams and rising to high office, he proposes to the heroine and tells her, “I never loved her. I married her only out of a sense of duty.” The male lead is devoted and faithful. But the reality is... Before placing first in the exams, he was destitute. Without the original owner's support, he could barely feed himself. He takes her inheritance to rise to high office, then turns around and cultivates the image of a devoted, faithful man? Jiang Heng says, “Since he's so devoted and faithful, I'll make it happen. Let him climb the ranks on his own.” As for her, naturally, she wants someone handsome, strong, and kindhearted. That's right: at first glance, she takes a liking to the rough man Xiao Mang, who rescued her from the water. He, Xiao Mang, is an outsider who lives by hunting. His household is small, and most importantly, he's handsome and well-built... and kindhearted. “Marry into my family, and I promise you'll have the best food and drink.”