Even in the real world there are a lot of random encounters on a battlefield. My cousin drove a tank with the Canadian Armed Forces overseas, and her column had multiple hostile engagements during routine transit missions. Both sides knew the other was operating in the area, both sides knew what kind of forces the other had, but her mission wasn't seek and destroy light infantry units, her mission was to drive her tank from base A to base B so they could be used to support missions planned during the following week.So you somehow know the opposition was not there with intent to engage?
If they were, then your cousin's convoy not knowing where the enemy would hit doesn't make it random - that makes it an ambush.
Anyway, that is the real world. It has a lot of more randomness in it, and that randomness generally makes it a bad, uninspired strategy game if you want to think of it as that. We're only motivated to play and practice it because winning has real-world rewards. I should know - I'm a army lieutenant in reserve and tactical analysis work is kind of my specialty.