> Slavs are at a distinct disadvantage against strong cavalry civs
Hard disagree here. Slav halbs with Dhruzina are some of the best in the game, Boyars are much easier to mass with the new Castle tech and trade fantastically with Paladin, and even nerfed their farm eco is incredibly solid.
That said I do agree with the concept, but am worried that if implemented it would have the Malian halberdier effect of getting the civ over nerfed in the future. It would make their cheap capped ram+Halb push super strong to auto have +3 shortly into imperial.