Main thing is just the flexibility of the civ since transitions are easier with the tech discount, their tech tree generally is pretty open from the blacksmith. Also the villager bonus at best is a solid constant advantage till mid castle age or at worst means you can lose a vill or 2 to a raid and still be equal. The civs is fine and really these types of eco bonuses are really convenient but once you reach your imp army comp outside of UU Chinese don’t have any advantage compared to alot of civs so wouldn’t say they need nerfing its just their a strong civ compared to the rest but not unreasonable.