Back in the day, I would just buy a new ram from a newly conquered city instead... easier that way. Apostles have 4 move, BUT you need to found a religion AND have a holy site, AND spend charges, so an apostle is consumed every 1-2 cities, and that really hamstrings any bonuses they have. A ram at 260 gold, doesn't scale, is far cheaper than an apostle (gets easily to 500+ per apostle once you've bought several). I wonder whether free heavy cavalry is that insane. With production cost cards, one would wonder whether it is better to just build the unit straight up rather than finish a whole district. (what this does allow is for you to produce them beforehand and then finish them right when you unlock the civic, otherwise you just get plain chariots) There will come a point where the district becomes substantially more expensive than just chopping out the unit. Moreover, it seems this comes really late (divine right) when compared to feudalism.