With some simple house rules attacking the true neutrals does not need to be insane.
In our group we are remove 1 inf in each of the mongolian territories and in angola and mozambique. This makes attacking an European true neutral less devastating for the asian land war and makes it less severe for the Italians. Its also more true to history which is a bonus.
We are also thinking of making Argentina as a pro-axis minor. This would be partly to make south america a possible theatre of operations and also to reduce the extreme impact on the american economy and manpower from attacking a true neutral. Not very true to history but we just regard that as a potential bonus.