The issue has been raised:
Are there any official rules stipulating that China may not have Armor, Fighter, Tactical Bomber or Strategic Bomber units bid for it.
I believe, per page 10:
China may only purchase infantry.
There exists an American plane representing volunteers that, for the purpose of movement and combat, is considered part of the Chinese army.
So there is a precedent that says, American units can volunteer for the Chinese army, so long as they do so prior to the start of the game, and that, said units, are considered part of the Chinese army for the purpose of movement and combat.
ATM, my league ruling is that these units may exist, and TripleA be d@mned for not allowing you to put them on the board. Unless someone can explicitly show me where they cannot in the rules, as printed by WOTC. (I knew these dang house rules for bidding would bite me in the butt one day, I just didn’t think it was going to take from Classic until now to do so! lol.)
I’m looking for rules that ban it, btw. Something like the rule, on page 10 of the Pacific SE book, that says, to the effect “China may not have an industrial complex” but it saying something like “China may not have armor, tactical bombers, strategic bombers, etc under any circumstances.”