yeah, it is more like a totally different region, as the landscape does not match up - especially in the south and the east there were mountain ranges in hte previous maps.
But that is to be expected anyway - where is the logic in going the same path multiple times? the backgrounds of all the stages should be different in my opinion... going deeper and deeper into the jungle
On the other hand, the stages could be interpreted as different landings over a period of time and the inhabitants get stronger every time as they assimilate tech on the previous invasions. At least that would explain, why each stage starts at the coast.