Hans Lemurson
Prince
One of the predominating military strategies in Civ is the Stack of Doom(tm), where all of your units travel together in a big group which allows the defender to always bring forth the ideal counter-unit, and brotects wounded units within from further harassment. It's true that this is in fact how armies historicly operated, but gameplay-wise, it greatly limits variety of combat.
My idea on how to limit the local concentration of forces is for there to be a combat penalty assigned to units in a stack of a certain size, like maybe -10% for every unit above 3. Stacks are still possible, and still provide all of the same benefits as stated above, but are no longer recommended as they make you very vulnerable. Great generals could possibly increase the threshold for the stacking penalty to 5.
(I got this idea from Hearts of Iron, where your units suffer a combat penalty for having too many in a battle, and/or lacking sufficient leadership. You also gained bonuses for attacking from multiple directions, but that's a different story.)
My idea on how to limit the local concentration of forces is for there to be a combat penalty assigned to units in a stack of a certain size, like maybe -10% for every unit above 3. Stacks are still possible, and still provide all of the same benefits as stated above, but are no longer recommended as they make you very vulnerable. Great generals could possibly increase the threshold for the stacking penalty to 5.
(I got this idea from Hearts of Iron, where your units suffer a combat penalty for having too many in a battle, and/or lacking sufficient leadership. You also gained bonuses for attacking from multiple directions, but that's a different story.)