I'd love to see resupply be handled in some areas and maps through merchant shipping. That would give new targets and a new dimension to the game. there could be escorted convoys, groups of three ships unescorted but armed merchantmen, and single ships, laden with supplies. They would transit form ports to ports and would supply us with new targets and allow the start to be more sophisticated (reduction in down times, rebuilding times--increased down times).
You could starve a team to death.
This would especially be sweet in Pacific and Meditteranean maps where shipped supplies impacted the outcomes so dramatically.
Sakai