Okay, alternate-universe time to answer your question....

"What if Sinclair had not left Babylon 5?" (Isn't this kinda like
the Marvel What If? comics..."What If Dr. Blake's Nurse Had Been The One
to Find Thor's Hammer?")

The differences would be more noticeable in the later episodes of
this season, rather than the first batch, which are still dealing in
large measure with the after-effects of the season finale.

So the first few episodes would have been somewhat the same in some
ways to what is there with Sheridan. The problem that I had was that he
was becoming (and would have become) mainly a problem-solver character;
there's a squabble or a problem between other characters who are rising in
profile (G'Kar, Londo, Delenn, etc.), and he solves the problem in some
way. These, to me, were the least interesting episodes of our prior
season.

It would've been necessary to bring in another character with a
direct connection to the shadowmen, since Sinclair's main connection is
to the Minbari, and it would've been straining credulity to plug him too
much into THAT story as well...hero of the line, missing 24 hours, Minbari
soul, AND a tie to the Shadowmen...c'mon, what else does he do, fly under
his own power?

Had he stayed, the Shadowman tie probably would've gone to either
Keffer or Garibaldi. Which, again, further removes Sinclair from the
main thrust of the story. He would have stayed on as more of an observer
of other people *acting*, while he *reacted*.

I can't get too specific otherwise without revealing, by contrast,
what's going to happen later on this season. Suffice to say this: watch
the show up to and through "The Coming of Shadows," "All Alone in the
Night," "Acts of Sacrifice," and "Hunter, Prey." (That's about episode
#13.) You can then ask the question again, but I have a real suspicion
that once you've seen those episodes, and what Sheridan does, you won't
NEED to ask, because you'll see how he fits into the overall story in a
very specific fashion with is 180-degrees different than Sinclair.

jms