Cumans nerf

I know that this has been discussed on this sub a lot but I think a reasonable way of nerfing the Cumans would to be have them start with -200 stone. This forces the Cumans player to either commit vils to stone earlier, which slows down the rest of their eco from getting too far ahead, also it allows the opponent the opportunity to try and deny the Cumans player their 2 stone piles which is a good counter to the civ, but at the same time allows the Cumans player the ability to build a 2nd tc in feudal age if they commit to mining that extra stone. I'm not really sure if this is the best way of solving the Cumans bonus but let me know what you guys think.