I just played a game against myself, knowing exactly what the entire Axis plan was, and I build and move specifically to counter my own attacks. I left UK practically unguarded and put everything they had into Africa and the Med from UK1 on. I removed the Sealion threat entirely and mandated that Germany wasn’t allowed to build transports - this allowed UK to basically empty out Britain which is highly unlikely. UK built for offense immediately.
My conclusion was interesting. I had a good chance to Capture Moscow on G5 but bad dice rolls ended this ability on a R4 suicide infantry attack which actually succeeded against a split German force. UK (who obviously had an easy and clean hand) dominated Italy and captured Rome on UK5. Germany was still poised to capture Moscow as scheduled on G8, but with Italy gone the game was over. USA was large with many transports, but Germany would have been fine against them and would never lose Paris.
On the Japan side, I loved the new dynamic in Mongolia - Japan can just totally bypass the Russian stacks.
My conclusion is that Germany cannot split its stack at all to capture outlying territory or Russia can pounce. UK can end Italy easily if they feel no threat from Germany.