Dimesdan hit the nail on the head, at least when it comes to minor conflicts as would be the case with the Ro article given in your example. My preferred option would be to keep the conflicting information in the correct chronological placement with the other information. This conflict would be clearly highlighted as has been done on the Wookiepeedia "Legends" articles. Rather than garish boxes at the beginning and ending, I would opt for a different color "box" that would fit around the conflicting information.
With regards to massive great conflicts such as the Earth-Romulan War, we could either plump for having them in the one article, but in clearly marked sections or go for separate articles.