I would say the main issue is that America is too good in a FFA. Unless you split the map ‘‘a la risk’’, but then again whoever gets the US is still too good.
The US can is not as much of a threat in a risk type setup as you might think especially if you downgrade the IPC value of the 3 territories to half the original value and upgrade the IPC value of the rest of the VCs to 4-8 IPCs each.
Plus North America is sea locked just like in G40 so it takes longer for whomever gets the US to be able to attack. So the defender gets at least 2 extra rounds to build up units.





