You are likely moving all of your units at once or in bunches. Try to move them in groups of 1000 around the map. Its a brute force method but you will win eventually. If I were you I would revisit the single player games and work on those until you have improved your ability.
I won too. Hint. Diplomacy cards are useless as well as blockade cards. You should keep fight. Each time game give bigger reinforcement cards. You should not keep all yourself. keep reinforce your allies If most of them survive you can win easily.
Vexos, I believe you. However, you can't share single-player games like you can with MP games. Try to click your own proof, and you'll see what I mean. instead take screenshots, for example, if you want to share