Lol, you clearly haven't played on Skritshell's server before. Strategic bombers in numbers are so overpowered they had to be banned.
2000 Strategic bombers over an airzone for even an INSTANT = goodbye airfields and have fun countering when the attacker can teleport his planes to any airzone at will. I don't know what kind of games you play, but if you don't need an Italy or Japan to win then your allied players are garbage.
Have you tried leaving 200 fighters in every airzone in europe? If you do that stratregic bombers are useless as they will all get disrupted, even if you send 10,000 of them. Then just have your Hungary move some planes over if they leave them there to long. Bam, Strats countered. Better yet, put 15 factories on heavy fighters with agility 5, you will shoot down their Strats by the hundreds with just 200 of them in your most important airzones and fighters on the rest.
Other than their being easily countered like i pointed out above, if the allies concentrate to any great degree on strats its game over. The allies are required to do a DDay on the day of Barbarossa, the Soviets will die to a snake every time unless the allies do. If you build any strat bombers, you are giving air superiority to Germany and sacrificing significant production that could have gone to mechanized and heavy tanks. Not only that, but the allies basically have no aluminium, making it impossible to win if you waste it all on Strats. You need to put every factory you can on Fighter 2s until their is no aluminium left to buy in the world. Then that wont even be enough, but you have to pray Germany is mediocre and it will be.
If Italy is pro, then i grant you they can help, but mostly its a win harder deal. I dont see it as fair that Italy can get 150 Mils and 100 Civs by mid 1940 and build by itself more planes than the allies can throughout the whole war (especially since they can build fighter 3s and the allies are stuck with 2s). So usually i just invade them and take their factories, as well as the factories from Yugo and Greece. Japan is entirely irrelevant, the only downside is that AI Japan tends to get invaded by the USA which gives them a few more factory slots, but that doesnt really matter as the bottleneck for the allies is Aluminium and not factories.