A couple of people in the Discord community have made the same point so you are not alone.
The first major update is coming 28 March which will add mechanics to land combat. You will be glad to hear several changes are being made to address this problem.
New properties such as manpower strength, attack and defence modifiers as well as division reinforcement will increase the value of each individual addition.
You will no longer move around individual divisions. Instead you will create a Corps of up to 5 Divisions. Each territory can contain a single Corps so a lot less micro for a more realistic result!
If you are someone that enjoys playing the game, I would encourage you to join the Discord to stay in the loop with development. As well as contribute feedback to the direction of the game.