In a good KJF, Germany will be stopped before getting 50 IPC, Switch. Any layman player who puts some thought into it can easily slow Germany enough to prevent them from being at the doorstep of Moscow before Round 10, at which point, Japan should be castrated.
The trick is to put 2-3 transports of troops into Africa a turn. Easy to do without building a single extra transport. Actually, odds are, you’re putting 4 transports in a round. Maybe more, if England is focused on Africa and fighters for Russia. America can take Japan without England’s help. Just use the English fleet to make it near impossible to sink the American fleet and let America take the islands.