I usually check multiple sources--or try to--before I change something someone else has done. You can add an additional wife with the information you have. You can remove the other wife. But you don't necessarily have to do both. Sometimes people married someone who died 6 months later. Maybe that info wasn't available to whoever wrote the book. If you remove the wife, you might explain in her biography that she was previously attached to [[Surname-444|John Surname]] as his wife, but that you removed it because it lacked a citation and conflicted with other information. That way, if someone finds a citation later, it won't be hard to re-attach her to the correct spouse.