No, he really wrote most of the episodes [1]: Creator and showrunner J. Michael Straczynski wrote 92 of the 110 episodes of Babylon 5, including all 44 episode

No, he really wrote most of the episodes [1]: Creator and showrunner J. Michael Straczynski wrote 92 of the 110 episodes of Babylon 5, including all 44 episodes in the third and fourth seasons;[63] according to Straczynski, a feat never before accomplished in American television. [1] https://en.wikipedia.org/wiki/Babylon_5#Writing https://en.wikipedia.org/wiki/Babylon_5#Writing