I'm sorry you were confused.
The order of battle and terrain were based on the GBoH scenario from the Barbarians expansion. You will have to ask them where they got their information from?
My solitaire and ftf battles of the scenario have, bar one, been very close battles, with the edge going to the Romans, which in my own opinion is how the battle should play out.
This far removed from the event it is impossible to be accurate on these kind of aspects, but I'm glad you enjoyed it after your changes.