Could you remove the Garrison as a feature? As I understand it, the value of defense is calculated without the Garrison, and if the Garrison appears, the number of units doesn't decrease. A recent example: I played a game where 38 Giants were stationed in the Castle. The Garrison generated, and they formed 5 stacks, resulting in 8 Titans + 30 Giants, which is clearly more than 45k value.
I agree. Also, remove the morale of neutral creatures, add unit upgrades, and hero classes.