see, im not so sure about that. i dont think it's just politics, because the examples i see are for land trading and obviously i dont know the DR situation but it seems that if two countries are similar in NW and land the % gain from the PS/SS is greater. so i was wondering if this is just a flaw in the example, or a new part of the game.

i tried to apply said similar NW+Land theory and it seems to work too.

eg. 8k acres 3m NW hits 14k acres 5m NW -> gain 1100 (1600)
while 10k acres 3m NW hits 11k acres 3m NW -> 1500 (2300)