@andrewaagamer yes, but, Axis & Allies is a strategy World War 2 board game. Any nuance and complexity should exist within the framework of historical reality.
The fact of the matter is that most of the game’s design decisions represent a trade-off between two mutually exclusive extremes. On the one hand, we have absolute historical fidelity (guess who wins) and on the other we have pure game design in which any change to improve play can be made.
While I agree with you that there is nothing game breaking about other nation’s fighters taking up carrier spaces, it is still a jarring disconnect from an historical fidelity standpoint. If the ANZAC fighters have been assigned to a US carrier why aren’t they taking orders from the US Admiralty and participating in US maneuvers? Why is Soviet Russia’s penalty for having 8 British fighters sitting on Moscow from turn 4 onward only the loss of a $5 bonus?
Certainly this is not the place for specific House Rules discussions, but it is important we remain conscious of the reality that thousands of people play this game, and that many of them disagree with us on everything, other than how awesome this game is.