I do know that with E:FC they completely jettisoned the original alien race and most of the main cast; and, with Andromeda, the final season was almost completely planet bound, with almost no spaceships.
With both shows, the ratings plummeted with the quality, but Tribune gave them both fifth seasons for purely financial reasons, in hopes of surpassing the 100-episode "magic number" for rerun syndication, in hopes of making a profit in the long run. As such, in both cases, the fifth season was retooled to be as inexpensive as possible.