There was a bit of a sci-fi cold war in the 1990s that many newer fans may not know about. Accusations of theft made the rounds as the creators of Babylon 5 felt that Star Trek: Deep Space Nine plagiarized its concept. There might be some truth to the claims, as J. Michael Straczynski apparently had meetings with Paramount about producing the show as early as 1989.
Yet, Deep Space Nine came around four years later in 1993, and Babylon 5 came around one year later in 1994. According to series actress Patricia Tallman, the two sides settled out of court on the matter, bringing in some degree to credibility to the claims. This may have been part of the reason there was so much bad blood between the shows and the fandoms.
The two groups never really got along and it never felt like the wider world of Star Trek embraced Babylon 5 as they did and would with other science fiction properties. There was certainly some contention and it's likely why Babylon 5 made some of the moves that they did. For starters, bringing in Star Trek icon Walter Koenig onto the show.
Koenig was/is a great actor but there were plenty of people to call, yet a Star Trek legend was called in. While it's not officially the reason why, as far as we know, the move felt like they were pulling one over on Star Trek. Even if they didn't intend for that to be the reason.
Koenig played Alfred Bester, a fairly popular secondary character on the show. He'd make 12 appearances on the show, sometimes alongside his real-life wife. It was a bold move to bring him aboard considering the issues between the two properties. Especially seeing as he was fresh off of his appearance on Star Trek Generations.
The move would end up seeing Koenig not appear in another Star Trek property produced by Paramount until Star Trek: Picard's final season in 2023. There may not have been any bad blood about Koenig working for Babylon 5, and it may have been a simple case of moving on from the Original Series stars, but the timing is suspect.
Koenig for his efforts, was easily one of the most interesting side characters on Babylon 5, playing a fairly unsettling Psy Corp officer. It was a stark departure from his loyal and dutiful role as Pavel Checkov. What's even more interesting is that the character of Alfred Bester was a late addition to the show.
Originally Koenig was set to play Knight Two, but an illness took him out of the running to play the part. A part, that would be far less impactful than the one he'd end up playing. So the series created Bester as a way to get Koenig on the show once he recovered. It was an incredible gesture, even if the two franchises were never buddy-buddy.
Koenig's run on Babylon 5 wasn't one with an abundant amount of episodes but it did highlight some of his acting skills that he rarely got to show off with Star Trek.