I found an idea on this forum that I loved, so I’ll share it with you.
Use the Larry Harris Tournament Rules 2.0 ruleset, of course, as the out of the box rules are broken.
Then, roll 2 dice for every country. These are the advantages the country gets. (Re-roll doubles)
Then, the Axis countries each get to choose 1 additional advantage. This gives the Axis 6 advantages, and the Allies 6. It also helps lessen the gap between the allies and axis balance, because the simple act of getting to choose one of your national advantages can be very strategic.
Too many advantages will make the game feel a bit cluttered, and probably disrupt the balance. If you play with all advantages, the allies get a full 6 more! Do NOT use the out of the box advantages (ever) because they will destroy the game, lol. The US Super Fortresses was the worst idea I have ever seen in a game like this, and after LHTR tried to balance it out, Harris (presumably) realized that such an advantage is gamebreaking no matter how nerfed it is, and replaced it all together (with an advantage reminiscent of Industrial Technology in classic, but balanced as land units aren’t affected).