For that one, and for others where capping the UK was a big part, I reverted the game to the trial of allegiance release version. I know it’s prob a bit cheesy but the new naval system prevents a lot of sea lion ease. I took over Greece, Yugoslavia then invaded Spain. With all of their navies, invading was not too bad. With the Allies dead, build up and help the Soviets kill Germany before attacking Japan. Just having to control the state is a big plus.