It would be great if the game could calculate the strength of opposing armies and only offer battles if they are roughly equal... Otherwise, battles only occur between unequal armies... The stronger one attacks the weaker one... I had an example: with an army worth around 70,000, I received an invitation to fight from a player with an army worth 200,000, and when I had an army of 400,000, I was attacked by an army of 1,000,000... That's how things are in this game :)