Why do Chaoshan people say that 199 1 year-old sheep (male) can't be with 1997 cattle (female)?

Chaoshan people pay great attention to the attributes and ages of two people, and Chaoshan people are also people from a relatively traditional area in China, so they often pay attention to some local customs and habits, so they pay more attention to these things than ordinary people and others, so they must have their reasons for saying that they can't be together, because every place has its own customs, so we still have to respect customs, right? If two people really have feelings, then if they are really together, I think it is ok.