Common market and naval improvements. (Fearless Blue)

Common markets in real life reduce trade barriers allowing better and cheaper trade. I think a bonus should be added to trade within a common market to represent real life allowances.
Corporation cant lose money buy selling cheaper to common market members otherwise people wont join common markets. Maybe a % profit bonus to the seller in proportion to the product sold on the common market allowing cheaper prices for buyers.
Maybe an international trade tax could be created that allows a common market tax to be set lower.

On the navy front units and supplies should be transported by sea. In real life this is how large quanties are moved.
Allies could then build ports in allied countries similar to the air depots now.
This would also allow the creation of transport ship units, marines and corps to produce them.

an alternative to a trade tax would be to introduce warehouse costs. if it cost money to store supplies (and products), then corps taking part in common market agreements could maintain low stocks and operate a 'just in time' policy, to reduce their storage needs and give a financial incentive to being in a common market.

Might as well add international railroad companies and turnpikes operated by enterprises.