Mopar had the same issue with redundant models during the 60's and 70's, as did Ford and Mercury. They saved on R&D that way. They wanted to keep those loyal customers who were with the original companies prior to the mergers. Came a time when all the old-timers had died off and the younger generations weren't so attached to a particular manufacturer, and the companies needed to get leaner -- because they put out absolute crap for over two decades and the Japanese and Korean companies were killing them.