First, thanks for your help guys
I really appreciate it. I cannot help thinking about B5 possibilities / original inception etc., though. Perhaps you want to share your thoughts with me on some of the arguments below?
necessitated adding a character like Sheridan in in some capacity even if Sinclair stayed, as it was too late to 'coincidentally' ret-con a connection to the Shadows into Sinclair's backstory, or introduce one while he was still obsessing over the Earth-Minbari war and the Battle of the Line.
Actually, I would really like to see the original outline right now *sigh*. I know that JMS did not want to involve Sinclair with the shadows on a personal level because he began to think that everything revolved around one single character, to the point of stretching credibility to a breaking point.
The problem seemed to be that it was an awful lot to do for a single man - train the rangers, fight the shadows, break away from earth, fight earth, perhaps resolve the minbari civil war etc. But I think that if you take away "train the rangers" (a thread which could also have been attached to Delenn, imho), we almost have what is done by Sheridan in the end (except the Minbari civil war), and I think it would not have been too much of a stretch to have Catherine Sakai become a Ranger, then go missing at the end of S2 (at the time Sheridan learns of the Icarus' fate).
Indeed, it would have been much more dramatic to hit Sinclair in the face with Sakai's fate at the end of S3 and the betrayal of Garibaldi at the end of S4. Especially when you consider that Lise Hampton was introduced at the end of S1 as a means to get Garibaldi involved with the shadows in case Sinclair had stayed (perhaps he would have been blackmailed?).
See, my problems with S4 are that so many things point to Sinclair instead of Sheridan. Garibaldi's view that the crusade against earth is not about principles, it's about the man, "his transcendence" who came back from death. Sinclair as Entil'Zha would have fit that transcendent and "cult of personality" role better. Earth psychologists explain that war sickness can make people want to look like those who defeated them (the Minbari) - again, that would fit Sinclair, who suffered a traumatic defeat at the Battle of the Line and dresses like a Minbari.
Sinclair's close ties to the Minbari that rose suspicions on Earth even in S1 and were laid out so carefully would have paid off in S4. The crews of ships loyal to earth are told by EarthGov they would be killed and replaced by Minbari if they surrendered. I think with Sinclair dressed as the Entil'Zha, xenophobia would have set in much more easily. The hole in his mind, his alien garments, his traumatic defeat at the Battle of the Line - all could have been used against him effectively in a propaganda war that simply does not fit Sheridan as well.
Well, that's my point. Comments are most welcome