That's because landmasses are wrongly placed in some maps - Great Britain should be in middle of map horizontally.apart from wrongly placed resources, which should be corrected and generally better match the real occurrence, I miss wild spawning elephants, camels, giraffes. (especially in Europe it looks all random, not according reality)
BTW: the GEM ist the biggest map I can run on my system with acceptable turn time (i7 with 3.3 GHz), so it is my preferred map.
Alaska should be in west corner of map and Russian most eastern tip should be on Eastern corner of map.
Longitude of 0 is center of map horizontally.
Use my No Latitude/Longitude limits mod for "broken" or otherwise nonstandard maps