Most of that was because of the last minute decision to produce the fifth season.
The end of the Shadow War was supposed to occur during the middle of the fifth season, with the last half of the season dealing with the aftermath.
During production of the fourth season, it began to look as there might not be a fifth so JMS had to decide which plot threads had to be wrapped up in case it was the last. The decision to produce season five came too late, so he had to come up with additional episodes to complete the series. That’s why it is an uneven season with good and not as good episodes.
I thought the original intent was a five year series. To me the loss of Michael O’Hare was a huge break in the show’s narrative continuity. To me the Sheridan character played by Boxlietner and the background created for him was an huge ill fitting puzzle piece for the series.
Yes, it would have been a much better if they hadn’t rushed season 4.