We know that some parts of the map - garrisons are a necessity to counter enemy cavalry incursions - or just de facto a garrison to keep vital supply lines or routes of transport in your hands. Important for the CSA.
Now what I see is during many games is that the enemy is attacking - with a small force - my city for a few days - and eventually the garrison is destroyed.
Ok, a destroyed garrison is not that costly for the war effort. However, it's still a lost unit to recruit again.
2 remarks =
After destruction - do you have the ability to regain them in the reinforcment pool to recruit them again - or are they permanently lost ?
I concur that a large invading force should result in the surrender or destruction of the garrison (garrison destroyed). However - I also noticed that 2 cavalry brigades (or raiders) destroyed an entire militia. Shouldn't militia be able to flee or retreat from the city if the opposing force is considered as small (small = 1 -3 brigades)?