It sounds like you have this sorted, but I thought that I would add this anyway.
Adding new divisions in - fiddling with ID numbers - sounds a little complicated. What has worked quite well for me in the past - admittedly with HOI:Arma saves rather than AOD - is to steal divisions from a minor / some country that otherwise would not normally need (the South Americans for example). As long as you have edited out the tag = xxx bit of the relevant division, it should be fine to be inducted into you army, perhaps with a bit of renaming for seasoning. For land / air units I tend to change them to an earlier model; this upgrades them to be on a par with my own units, and gives me a bit of a penalty for cheating to balance things out a little. For naval units, things can get a bit hairy, but if you replace the relevant data with that from you native units, you are golden.
Hope this helped / provided another useful and fairly simple offer for you to use,
Amartus