@WiseOdin
It's a lack of imagination at work when people say that the addition of airborne units would wreck the game. First, the addition of paratroops would make the game more closely resemble the real war in western and southern Europe, where the Germans, British, Americans and British-supported Poles all made significant drops of airborne infantry (not to mention a multiplicity of airborne drops of small commando units). Second, as to the "parade of horribles" presented as excuses not to add a new airborne unit, the actual WWII history provides the answers:
1. Airborne troops were ELITE troops, and their NUMBERS WERE LIMITED because (a) they were expensive to train and maintain; (b) they were time-consuming to produce; (c) even the United States, with the largest air force and the largest fleet of air transports in the world, could not air-drop more than than two airborne divisions (6 to 8 airborne infantry regiments) at any time.
COW SOLUTION No. 1: The number of airborne regiments that any one player may possess at any given time must be strictly limited, either as a percentage of total infantry units (e.g., 15 or 20% of all infantry regiments a country has) and/or by a set-number limit not to be exceeded regardless of the size of the country or its army (e.g., 8 total airborne infantry regiments).
COW SOLUTION No. 2: Airborne infantry regiments should cost two to three times as much to produce as conventional infantry regiments because they are more expensive to train (including an oil/fuel resource requirement like motorized infantry), they should require three or four times longer to produce than conventional infantry units, and they should have a higher manpower maintenance/replacement requirement because of their inherently higher injury rates. Resource production costs should specifically include an oil requirement, as well as rare materials (i.e., silk/nylon).
COW SOLUTION No. 3: In-game prerequisites for production of airborne units should include completion of L2 or L3 infantry research, L2 tactical bomber and/or L2 strategic bomber research, plus L1 airborne infantry research, as well as an L2 barracks and an L1 air base.
2. Properly used, World War II-era airborne troops could break tactical deadlocks by circumventing coastal defenses or other natural defensive lines (e.g., rivers) or man-made fixed defenses (e.g., border defenses and fortresses). That said, there was nothing miraculous about paratroops, and they had significant real-world limitations, including their extreme vulnerability to interception by enemy fighter aircraft and anti-aircraft fire while they were being transported and during their descent, they lacked the ability to sustain themselves for more than several days without being reinforced by ground units and/or resupplied by air drops, and their air transport range was also limited by the return-trip range of their transports as well as the practical consideration that they could not be dropped more than 15 to 20 miles behind enemy lines. These limitations suggest several more in-game solutions:
COW SOLUTION No. 4: To better represent their real-world vulnerability to fighter interception and AA fire, the hit points while being transported by air should be reduced to no more than 5.
COW SOLUTION No. 5: To better represent the fact that airborne regiments were lightly supplied in the real world, their hit points should not exceed 12 (compared to 15 for conventional infantry).
COW SOLUTION No. 6: To better represent the limitations and vulnerability of their air transport, their in-air range should not exceed the ability to penetrate more than two enemy provinces or 50 to 60 miles into enemy territory (however defined).
3. Because airborne troops were forced to carry all of their equipment by air transport, they also faced significant limitations in anti-tank capability and had minimal motorized transport once they were dropped, suggesting several additional in-game solutions:
COW SOLUTION No. 7: To better represent airborne units' status as light infantry, they should have reduced offensive and defensive strength against enemy armor units relative to conventional infantry.
COW SOLUTION No. 8: To better represent their lack of significant motorized transport once they were dropped in enemy territory, they should be somewhat slower than conventional infantry when moving on the ground through enemy provinces.
In summary, I envision an airborne infantry regiment with 12 hit points on the ground, 5 hit points in the air (with no inherent defense against air attacks) or in ocean-going convoys, that is expensive and time-consuming to produce, that is more expensive to maintain than conventional infantry, that is strictly limited in number, that has practical limitations in its air transport range, is weaker against armor (but equally strong against other infantry), and moves somewhat slower on the ground through enemy territory.
