Total Eclipse happens roughly at the same time as the main series.
The situation in Total Eclipse is better because it takes place in America, which is BETA free.
The US achieved this by nuking Canada to oblivion when the BETA attempted to land there
Schwarzesmarken happens in the 80s, before Europe was overrun by the BETA.
Which means the entire plot of Schwarzesmarken is utterly meaningless since in the end everyone becomes BETA food anyway.