not to mention the book's focus on creating characters meant to play in a faux-Asian setting (a suggestion in the book that one should not use the material and instead use Western characters seems unlikely from a sales standpoint). I'm happy to be corrected if the book did in fact simultaneously and explicitly do all of these things...
Honestly, I am not sure if it appears in the OA book itself, except as basically a "you could do this", but the OA module series postulates a whole campaign which starts with 'western' PCs traveling to (IIRC) Wa, and then a whole series of loosely linked adventures going forward from there which take them to the various other major polities of Kara-Tur. While I wouldn't exactly label the whole thing "westerners rescuing the East", it is possible to construe it that way (there is some "high level PCs rescue rulers" kind of action, though generally the rulers are themselves super high level).
Beyond that, MECHANICALLY, the OA classes are combat monsters! Martial Arts rules basically mean they are 2-4x tougher in melee combat than a comparable level fighter or ranger. The spell casters are more of a mixed lot, but even the Ninja and Yakusa are probably no more hapless than their western counterpart, the thief (which is pretty weak overall, but still playable in 1e).
In general, I feel like the whole OA presentation is fairly cartoonish; its 'Fantasy Japan' (2 of them oddly) certainly hits all the basic Hollywood tropes. Ninjas lurk in all the shadows, haughty Samurai overlords maintain a ruthless cultural hierarchy, etc. Of course this is not absolute either, if you read the adventures there are all sorts of fairly 3D characters (in at least some of them) that have all sorts of motives and personalities. Still, the whole thing is a pretty superficial pop-culture presentation. Even so, some things like the status of women is handled in an a-historical and more egalitarian way, probably because it suites play of the game (IE you don't want female characters being downtrodden).
I think it is interesting to contrast that with the way Western society of the medieval period is portrayed in the rest of D&D's rules. It is somewhat cartoonish as well, which is to be expected. However, there is more material there, and if you were to dig into the 1e DMG, for example, there's a lot of material there on social structures, governance, economics, and other aspects which is, if not exactly scholarly and complete, is at least drawn from what appears to be a solid amateur understanding of the historical period, coupled with a conscientious attempt to present the material in a form which is both gameable and not wildly inaccurate.
At the very least, I think we can say that it is a fair assertion by Kwan that OA was written by "3 white guys" and it shows. It was also written FOR white guys who were playing out games based on stuff like "Kung Fu" or "The Seven Samurai." There isn't really an attempt to make it more authentic than that. I don't think Cook et al were not interested in the reality of Eastern Asian cultures and such, but they had limited in-depth knowledge, not a lot of research time (the book was written in a VERY short time frame after the original writer failed to produce a usable draft), and for a very non-critical audience who wanted Cartoon Asia. Some of it reads as a bit painful in this day and age.
OTOH, I think the authors and editors had a genuine liking and respect for Asian Culture. I haven't heard any of them speak up on their opinions, but I'd be surprised if the tone wasn't something on the order of "We may have made some mistakes in how we portrayed things, but we really weren't trying to treat the material casually or with any disrespect." I guess I could be wrong, but having heard most of the old-time TSR AD&D guys speak on various topics, they sure don't strike me as jerks or highly prejudiced folks, in general. I also suspect they'd do it a bit differently today. It isn't like TSR was anywhere near as polished a publisher as WotC/Hasbro is today.
