After playing quite a bit on the AI and trying out build orders, I felt the question had to be asked, why would you ever choose one of the slower age up options when playing as a LA civ? Most of the LA civs, except for maybe Colombia, only need to train an extra villager to gather the additional 200 food needed for the 1000 food politician, which combined with the research time reduction means you age at least 35 seconds faster and with an additional villager. Granted you have less time to gather resources in transition to colonial, but the extra villager trained in discovery, the earlier first colonial shipment, and additional 1-2 villagers trained in early colonial compensate, meaning that (I haven't done the math so I am going off of purely comparative logic) you end up with about the same number of resources as you would by the time you would hit up with a slow age, and more resources as the game goes on as you have 2-3 more villagers.
Provided what I have said is not untrue for some reason I have failed to see, why, then, would you ever want to use one of the slower, cheaper, age up options as an LA civ? Same goes for the later ages as well.