No offense, but you can't claim that a show takes place in a specific combination of geographic location and nationality when it explicitly doesn't just because of some cultural similarities. Never mind that you're talking about SF series which aren't anywhere close to that, even something like ZnT couldn't reasonably be claimed to be set in Europe -- it's a fairly close approximation of Europe in both respects, but the religion, social order, history, geography, subsurface mineral deposits, &c. all have fairly radical differences.
Macross Frontier (whatever else you may think of it) isn't set in Japan just because a large portion of their culture resembles that of Japan. The first part of A New Hope isn't set in Tunisia just because that's where it was filmed. It's sort of related to the "one unicorn" principle in writing, except emphasizing setting rather than suspension of disbelief. James Bond operates out of Britain because Britain in the Bondverse is essentially the same except for minor deviations related to how MI-5 and certain other groups operate. Zombieland is set in the U.S. because it is still recognizably our U.S. with the one change of "after the zombie apocalypse". Likewise, High School of the Dead is set in Japan for pretty much the exact same reason.