I do not believe this is true. You can have more than 1 city per world, as long as they do not violate the "pushing" rules. I believe one example is to have an elven city and a human city.
Although I only has 1 city and also i only play 1 world
but, it is my understanding u can have more than 1 city........in fact, u can have tons of cities
the critical issue is the IP address...Inno will check it
u need to declare (e.g. husband and wife and kids are playing), declare what......shhhhhhhhhh
it is not elven city or human city...I believe it is the boosted goods is 1 of the advantage
if u can have all goods that can be boosted in various cities, u do not need to rely on suplies by fs members and strangers
I have no idea whether it is considered as a "push" or not if u set trade..give 500 marble ( your boost) to get 1000 steel (other city boost) , as it is unfair trades,,,it is helping to transfer and balance your goods...
Regarding the topic reaching province limit
the recent event quest require player to scout (no alternative)....so even u reach provinces limit, u need to scout ( u may need to continue over the limit if u do not have a province to scout.) and conquer some sector in provinces
There is no change in playing..just super super slow slow to capture more provinces ..leave room for scout and capture sectors inside provinces (even it reach limit) as event quest require
But the game playing is never related with gaining expansion thro capture provinces
It is past history
b4 reaching provinces limit, try to change your playing to PLAY TOURNAMENT
u get more kp from tournament to grow your ancient wonder and tech tree (new chapter)