What are 2 reasons ancient people didn't wage war in the winter

Hitler tried it and failed horribly, Napoleon tried before that and found equally terrible results, and the Swedes who fought in the Great Northern War would tell a similar story.

Supply lines running thin in the freezing cold and enveloping mud spells doom for anyone attacking into a Russian winter - or does it?

For some reason, history tends to overlook the many times Russia has lost in the cold, despite their home-turf advantage.