A couple of things:
1) If you want the latest scenario then let me know. It isn't necessary though, just an option. ;)
2) I have since discovered that a game engine change will be required (in the next title, and will be carried into F14 after that) which limits the rail capacity at certain dates of the campaign. It should be a house rule that neither side EMBARKS units into rail mode before August 27th. On and after that date is fine. This is because rail capacity was essentially occupied fully at the start of the campaign, with mobilization duties. EP14 is fine here, use rail movement if it is available - only F14 suffers from this.
3) I noticed in the first post that you said 'custom optional rules to promote realism'. Well, I went through great pains to balance the game with the default optional rules and also took realism into account (of course) and I cannot see what changes you would make to them to 'promote realism'. All I can say is, the scenarios were balanced with the default rules, so change them at your own risk - I wouldn't recommend changing it too drastically for the Grand Campaign though. Just saying.