One of my favorite things to do in Civilization 4 was the one city challenge. It was really fun to concentrate on one super-city, struggling against the rest of the world. I never liked huge empires in any 4x game, really.
Would it be possible to add a challenge mode to LH? Either a "One City Challenge" in which you can only build one city, or a "Three City Challenge" in which you could only build one of each type of city (fortress, conclave, village). I know you can do this by yourself without any special modding or adds, but the key to fun in Civ4 was that these were mega cities; they could build all of the buildings with no limit on national buildings or building number prerequisites. In an LH one/three city challenge, in order to balance it, you could let a city choose TWO special buildings on level up. And perhaps a base bonus to growth.
I feel like this would add a lot of fun with a small change.