For me, the best way would be for you to put your inputs into the existing DB format.
Use the BoA 1775 (alt) DB as a template [WIA will look the same]. Don't worry about unit types, script syntax, etc., but rather give the unit name, strength [in manpower, not companies], date and location of arrival. That gives us a common format, easier to read.
Indicate Generals in each location/arrival group also if you know 'who went where"
My thoughts and approach:
From what you've posted, I've gotten the Brits looking pretty good, but the Germans are more confusing. I've located more references on them for a backup. Still in progress.
The Americans are a bit different: the initial setup goes the same way [and is pretty close], but the 'Autoraise/dismiss' function makes the rest of the war's appearances depend on how the war progresses [as it should]. Biggest challenge is to determine what 'upgrades' [militia to infantry] to script vs. rely on game mechanics of training and experience.
Once all is done, the play testing may drive some 'balance adjustments'.
I too want WIA to 'be all it can be'....