I now think a similar idea could apply to Finland.
Its 4 infantry can only move in the following territories:
Finland
Vyborg
Karelia
Norway
Sweden (not if the Axis are at war with the strict neutrals)
There are a lot of goofy moves and strategies that come from being able to move an unlimited number of planes an extra space when they start on an airbase (e.g. German all bomber strategy; Japan India crush).
So here is a rule to bust it:
An airbase with no more than 2 damage points can extend range by 1 space for up to 3 planes; not unlimited planes as in the standard rulebooks.
If an airbase has more than 2 damage points would therefore be 3 or more which means it’s not functional at all.
I think 3 is too restrictive.
I would be ok with trying a house rule that requires:
1. Air Base is completely damage free for any extra movement range period.
2. 3 plane types could move an extra movement point; not unlimited… So, 3 bombers, 3 tacs, 3 fighters…ect.