This thing with the first of 2 players having a huge edge over the other is a uniform problem with large maps with multiple bonusparches.
It's not something typical for Pearl Harbor.
There is a general solution that works for all these maps (like Waterloo etc..) and it should be simple to implement:
1) DON'T START 2 PLAYER GAMES WITH THESE TYPES OF LARGE MAPS.
(duh-

)
That was the simplest solution.
2) Implement many , many, many more neutrals on the map. So each of the 2 players should not start with more starting territories than they would if playing in a 8 player field (something like 9 territories ?).
There, simple and effective !

Barbarus hic ego sum, quia non intellegor ulli.