I'm sorry but duplicate your strategy.... We had no plans to starve the pm of food until the last 10 days.
furthermore you have just stated that no other nation is safe to build farms without being wared. When not even a 4 man nation can join in. That is why people leave, they are to worried about what their allowed to do rather than playing the strat they like.
lastly the fact that you did it right after maintenance is cheap yet effective.