Military Caste gets mentioned but Oligarchy doesn't get mentioned. The two synergize really well because it means +1
, +2
, and a unit you don't have to pay upkeep for. I know this article is about happiness, not gold, but putting a unit in every city to gain the +1
+2
from Military Caste can possibly be economically unfeasible, especially if you want to use military caste in the classical era while capturing lots of cities. If it's economically unfeasible, you can't implement the policy in the first place. Basically a waste of a policy.
Furthermore, If you compare a garrisoned city in a civilization with Military Caste to a coliseum, the coliseum provides twice the amount of happiness for the same upkeep in the classical era. As upkeep per unit gets more and more expensive as the eras go by, it becomes more and more inefficient to place units in cities strictly for happiness (with a +2
kicker). Oligarchy, on the other hand, removes the largest negative of applying Military Caste. As a bonus, city attacks are stronger due to Oligarchy. Normally this is negligible unless you get ambushed, but having a large army and many enemies due to the army's size + diplomatic penalties from declaring war on other civ's friends makes the chances of ambush higher than having moderate army size and a less aggressive foreign policy.
Also, even if an economy is healthy, Oligarchy can make Military Caste even more attractive and the gold saved can buy courthouses/happiness buildings or even more units.
Lastly, there's a diplomatic boost/penalty to using Military Caste. If you're putting units in all your cities, this can seriously deter other civs into declaring war on you due to a large army. Sometimes it will even make some civilizations fear you. On the flip side, it can cause an arms-race as other civs try to keep up (which can be a good thing -- it means they're not improving their cities). Also, some civs won't like you for having such a large army -- Mongolia is a shining example -- and you'll get denounced.