Given Ye Zun's massive, weapons-grade Issues, he would hopefully be in therapy, which would give him the toolkit for dealing with niblings, eventually. I don't think his prejudices against Haixingians are of the same caliber as Zhao Xinci's against Dixingians; it'd be more brother issues à la "Gege has EVEN MORE people he cares about more than he cares about me .____." I'd imagine that he'd also be at risk of becoming overly attached to the little things that like him. Then they'd have a much too indulgent and overprotective extra parent to shoo off.