If you break the tripwire rule, invading Turkey and Spain are no brainers, anyone who can do it should do it, its not just the income but the new paths opened to the money zones.
What people are essentially saying is that they want to add 10 new minor powers to the game. I suppose that’s fine, but they are just like defended territories that cannot fight back, they take time to design balance set up, and may just sit there for the whole game. Someone got ahold of some taupe colored HBG infantry at the tourney, these make good neutrals.
These ideas seem more appropriate for GW36 or a game that starts with more choice and complexity. This “minor powers” concept was tried in the 1914 AxA and its complex and confusing.
If it just adds more territories to be attacked and killed by Germany, Germany will do that early and often, they have abundant power to attack all the (worthy) neutrals at once already. America has its own neutral zone, but at 6 IPCs and in the wrong direction, its not comparable.
There also aren’t any on the Pac board, so again it seems to address Germany most clearly (as the power to kill/take any neutrals in range and the forces to do so lie with Germany at game start)