The post is a little old - but no, there is nothing beyond 20 level 10 farms and a well. Max population per city is 7650. Period. End of subject. Depending on walls and stuff, I sometimes have found it necessary to destroy troop buildings - barracks, workshop, stables to free the necessary population for a level 10 obelisk. And, there is little or no room for troops registered in that city. I put my temple in another city, too.