Originally, Chu Heng had looked down upon Mo Yan, believing she was not a worthy match for Xiao Ruiyuan. He felt that Mo Yan, coming from a poor background, had not been nurtured meticulously by a great family and would have difficulties adapting to various aspects of a great family's life, which could, inevitably, lead to conflicts between the couple over time.
Although his opinion of Mo Yan had changed later and he acknowledged this future sister-in-law, that concern still remained. He had Xiao Ruiyuan take two nurses back home with him, partly with this in mind.
Moreover, there wasn't really any elder at Lord Wei Yuan House who genuinely had Xiao Ruiyuan's best interests at heart. Regarding the matter of the Mo Family presenting the betrothal gifts, it was also Chu Heng who had entrusted his own Crown Princess Consort to handle it.