As Sweet tooth said i don't know if that can be added here in scourge. About the limit of planters per player, i'm not against of something like that but where should they put the limit?
We have noticed that this Jan map has atleast for us the worst performance since we are playing here in EU scourge (i can't imagine US server with more players) and one of a few reasons may be that all the monuments/populated areas and outpost&bandit are close to each other and surrounded by rivers and swamps and you just need to add a few farms there to make it worse. It doesn't have to be a 1000 planters farm. Devs should keep that in mind for the next maps.
We had a farm with +400 planters near outpost (3 floors), first day was ok we were alone there good performance, 2nd day ok, 3rd day i started to get bad fps sometimes ,checked outside and there was only 2 small farms nearby, lets say 40 planters with 2 PJ's. On the fourth day i loged in and i was getting 30 fps inside the farm checked outside again and all was the same. We have downgrade the farm to 1 floor and 144 planters and we are getting the same bad performance.