I'll echo what I said a while back in another thread.
AI's don't understand garrisons, but players THINK they do. If there is
Zero benefit to putting a garrison in a puppet city, then new, and non-forum players will be at a clear disadvantage. Players think that garrisons are good in cities because:
- they are good in non-puppet cities
- they see the little number above the city go up
- there are policies which reward using garrisons explicitly.
- garrisons are in cities IRL
As of right now there is no intrinsic benefit to having a garrison in a puppet, but players will either be ignorant of that or garrison in Puppets anyways from force of habit.
The puppet mechanics obfuscates the fact that garrisons have no benefit. As a result, you are balancing more for the AI's ability to play the game by hurting a human's ability to grasp the mechanics. Moreover it feels like the game would be tricking players, conditioning them into gameplay habits which are actually hurting them. At the end of the day, remember that you're making this mod for humans. Dumb, fallible humans who are susceptible to psychological shortcuts and suggestion.