Unfortuneately, when playing with victory cities, this is the case. But we never play as such, and im my opinion, a realistic game should be played without it.
Other than that, KGF is the only realistic strategy to win the game. Ignore Japan as much as possible. Yes send the Pacific fleet over to the Atlantic. It gets their in one turn. Then spend what you have to, to slow the Japs. How much, it really depends on how efficient the Japs are and some luck against the Germans. You cant totally ignore the Japs, but I would in the beginning.
To anyone who would say that a good Japanese player would take the first few rounds of being ignored by the US to achieve a complete Axis victory, I would reply, a good German player would achieve an easy victory for the axis by the US ganging up on Japan.
The real action will always be in Europe being careful to not let Japan run wild.
Silly and unrealistic National Objectives have changed the extent to which this is true, but most of all is the Victory city condition. I have seen many victories by the axis based on the number of cities they captured at the end of the turn, that by no means were obvious victories and worse, inefficient uses of resources for temporary gains that could never be sustained and easily lost.
But whether or not the city victory conditions make sense i guess depends on your definition of a victory.