There is no logical contradiction between the fact that some nations covenant with Christ in the last days but yet Antichrist rules over some nations and wars with the saints. I think even a lot of Reformed people default to the Left Behind mindset that Antichrist rules the entire globe by a supercomputer.
This allows for several things. The amil wants to affirm the NT passages about falling away and a darkening of culture. The postmil wants to affirm the passages about nations coming to Christ. There is no logical contradiction between these two statements. Many historic premils have successfully affirmed both propositions.