Hi Mathias,
Thanks for posting. I think your service and global experiences would be a plus to your profile and schools would be interested in having someone with such an interesting perspective in their class. I'm not even sure I'm following what your main concern is? The fact that your background is less common I suppose? That can also be a positive, not necessarily a negative, as it helps you stand out from many applicants, and schools are looking for diversity of all types within the classroom. The main thing to remember is making a solid case for the WHY... why is business school right for you? How does your past experience fit in with the MBA and your future goals? If you can successfully answer that, then you'll be considered for sure (with a good GMAT/application). If it does not appear to make sense (i.e your stated goals vs your background), that could raise more q's. In terms of your school background, the b-schools will look at how competitive your undergrad program was within your own country, sure. So overall it sounds as though you are well positioned, just work on that GMAT and keep us posted with questions! Good luck.