Hi kebabcurry,
Thank you very much for your post. Let me start by apologizing for the other GMAT Club members who thought it was appropriate to comment in this thread (and share insensitive remarks, no less). One of those users and comments has been removed. (Please ignore the other one as it as almost equally inane.)
Your international work experience will be an asset for you, though it will be incumbent upon you to "unlock the value" of the professional experiences, personal growth, challenges, failures, etc. that came from it. The nature of your clients (and client work) is intriguing. So is your cultural immersion and the fact that you were the only "anglo foreigner" on your team. All nice on paper... but the key will be telling the story of why all of that is important, matters, shaped you, influenced your world view and career goals, etc. The job itself is more "tier two" than "tier one," but the international element can definitely help boost that, so long as it's properly told.
Your GMAT score is solid but the quant percentile will, to your point, hurt you some at competitive programs. Your quant undergrad and quant work experience help, but if you took the GMAT with little preparation, got a 720, and think you can strike higher on the quant side, then I recommend pursuing a re-take. 720 is a solid score, but if you can boost your way up to 740+, that will have a meaningful impact on your chances and will hopefully do away with the "soft spot" that you current quant sub-score creates.
(By the way, focus on the quant but don't ignore the verbal when you re-prepare... you don't want to swing entirely the other way with your second take. Key in on the quant but remember to keep the verbal fresh, too!)
As I'm sure you know, the schools you've mentioned are very difficult to get into. The programs you've listed have three of the four lowest acceptance rates in the U.S. HBS should be approached as a long shot for almost everyone. That doesn't mean you shouldn't include it, it just means you should know you're shooting for the stars. Boost that score, tell your story, and give it a go! Sloan and Haas will be tough, too, though they're more achievable than HBS, and by all means your scores (ideally with an improved GMAT / quant sub-score) and experience entitle you to apply. Sloan is fairly small and Haas is very small. They'll be tough. Not many seats to go around. A lot will come down to application execution for you.
I encourage you to consider which "international brands" you consider worthwhile enough to include your application strategy. I'm not suggesting that you include programs for which you don't perceive the right amount of value in whatever market you're in after the MBA, but your current list of schools likely warrants some lengthening and diversification. Right now it'd be a very, very aggressive strategy. Happy to help you sort that out and answer any other questions you may have. Please feel free to sign up for a Free Consultation via the link below.
Best Regards,
Greg