Xuanji and Mo'er's personalities were actually similar, but what differentiated their lives was the existence of Gu Mohan.
Although Tang Mo'er had a bumpy childhood, she had found Gu Mohan in her life. Gu Mohan loved her for who she was entirely, he hadn't given up on her at all. Even though they had all of the obstacles surrounding them from Huo Yanmei and Gu Tianling, Gu Mohan was willing to trust Tang Mo'er and he stood by her side to support her all along. Through it all, Gu Mohan would always have Tang Mo'er's back, he would never let go of her hand.
But Lu Jinwen was different.
Lu Jinwen and Gu Mohan were completely different. Though Gu Mohan had grown up in a broken family, he was resilient and had an encounter with little Mo'er. Gu Mohan was loyal, steadfast and unwavering.