I made two new rules to that can help change strategy and make the game more historically accurate. They are air transports/paradrops. You need bombers for this. For air transports, you can carry anything you can on a transport on a bomber and land it in another friendly territory where it drops off all units in the air transport, but aa rules apply if you fly over an enemy aa gun. Also, once the bomber lands it stays in that territory for the rest of the turn. In paradrops, you take a bomber and use it to transport 1 or 2 infantry to either an enemy or friendly territory and then fly it back to a friendly territory. Again, aa rules apply. Also, when paradroping into enemy territory the bomber can't be used both to paradrop and bomb, you either send in two troops or use it to bomb, not both. Also, if an aa shoots down a bomber with units on it, the bomber as well as the units are lost, and if attacking an enemy territory with an aa gun with paratroopers, the aa gun fires at the bomber before the paratroopers are drooped. One more thing is that you cannot use bombers used in an attack, airdrop, or bombing raid during the combat phase as an air transport or to paradrop into friendly territory in the noncombat phase.
Another new rule I made is neutral armies and territory value. With this, you give neutral territories armies and value so that it becomes legal to take these territories, but you have to fight a neutral army first. Also, as soon as you attack a neutral territory, the territory and troops in that territory are turned over to one of your enemy nations until you take it over.