Ha, funny! I did not notice there was another idle update just today (thanks JK_3 for pointing this out in another thread)! I think it just improved this problem, possibly fixed it: https://www.warzone.com/blog/index.php/2020/12/update-5-07-9/
"...Second, the way attack sizes are calculated was overhauled. Prior to this update, when someone attacks you, it used your armies/sec value as the basis for determining how many armies it took to re-capture the territories you lost in the attack. With this update, it will not look at your armies/sec value and instead will base the attack size purely off of how much time has passed in the battle. While this may seem like a subtle change, it actually has a profound effect on the strategy used in battles. Now, getting a higher armies/sec will be much more beneficial than prior to this update..."