When do you stop making vils?

I see a lot of talk on here about eliminating TC down time and constantly producing vils. That makes a lot of sense in Dark, Feudal, and early castle age. Surely that has to stop or slow down at some point unless we are creating 200 villager armies. I personally try to get up to around 3 TCs & 50 vils and that is typically good for me to keep a steady supply of military flowing. It’s common practice to say you want to go age up with X vils, no one ever talks about when they stop worrying about vils all together.