Actually, if ever added to the game having a selection to carry 10 troops or be able to carry supplies should be an option. While not the primary use of the PBY, the PBY were used to ferry raiding parties behind enemy lines quite frequently.
PBYs were also used to ferry supplies to these men whenever possible in addition to resupplying coast watchers.
While I'm not denying they were used to move people, they were not a de-facto transport. They had no capability to drop paratroopers, nor airborne supplies. They would land at secluded beaches, and people would climb into a dinghy rowboat, paddle to shore, and make several trips.
Far cry from the basic mission profile of an air transport...