Maybe MakeHuman could be useful for some of these tasks.

Yes but that’s usually something newer players will do; not pros. There is no point of having 4 barracks if you don’t have the economy to always keep them training. Depending on the value of the production building, let’s say a barracks, you could have enough wood for 4 or 6 more soldiers to increase your wood intake depending on civ. It’s a problem I see a lot with newer players and even some “veterans” make. Nussantara in particular will build 6 stables when he doesn’t have the resources to train from all 6 so one or more is always idle.

Yes, you do have to get gatherers and stuff, but then you can just build like 20 barracks or something; it doesn't seem very economical to me. That's fine if you don't change it though 

Should I add advanced cav for every civ?

Perhaps GitHub could be an option?