Are the Shadows even going to kick things off in this timeline at all? The Minbari as a client species of the Vorlons, represent their philosophy right?
Thinking about it, the fact that the Minbari lost several massive fleet battles in a 1v1 against Earth is really damaging to that philosophy...
Another thing to note is that the armour scheme used by the Omegas was apparently better than what was used in the Novas. It seems reasonable that new builds might use that armour and thus increase the survivability of new build ships.
I do have to question Branmers logic on attacking Earth, his stated objective was to force Earth into accepting a face saving treaty with the Minbari.
And there lies the problem doesn't it? Attacking someones homeworld inevitably causes a grudge. So on the one hand - you succeed...