It should be noted that General Susan Ivanova is asked by Delenn to take the role of Entil'Zha in 2281 (cf. "Sleeping in Light") as Sheridan is dying. From what we can see, she accepts this post as she is finding her role as an Earthforce General uninspiring:
"I feel like an old war horse, trotted out on parade so all the kids can point at it."