Some suggestions I have for the game:
Part 1 (Important)
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- Weaker armies: basic capacity of only 1 unit per army. It would still be worth it because it becames a faster unit with a Blitz capacity! (this is not scen related, but more Civ related)
- Change in Leaders: make them able to rush improvements (to compensate for the loss of army power)
- Monarchy: have trade bonus and good unit supply support. I suggest removing "trade bonus".
- Reduce battle defensive bonus of coast, sea & ocean. Why do defensive units got an advantage? My suggestion would be 0%.
Part 2 (Minor)
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- I-boats stronger than Allied Subs
- Allied Adv Submarines stronger than Japanese Adv Submarines
- Strenghten PT Boat: Radar, slighter stronger attack, higher movement points
- Less change of terrain: make workers much more expensive and slower. Specially in building roads, railroads and airfields.
- Make Guerillas and rifleman able to be transported between airfields (airlift?)
- Make Subs (all types) and PT-Boats able to make stealth attack also against other ships: Battleships, AA Cruisers, Destroyers, Adv Destroyers, etc.