I've been thinking for a while about the problems with the way previous HoI games have modelled things like air warfare and convoy raiding by submarines. Previously, these actions have been modelled as symmetrical battles between organised forces, which really isn't the case. Submarines for example, don't operate in massed flotillas, and don't attempt to slug it out with surface vessels in rounds of combat where both sides fire. Rather, they tend to act as solitary predators, firing off some torpedoes at a target before diving and praying. Similarly, aircraft don't normally operate like fleets in the sky. Whilst big missions did occur, smaller missions by as little as a flight or even single aircraft also did.
Because of this, I feel that some form of abstraction is needed for submarines and aircraft, which removes them from the map and allows them to be modelled more realistically. The best solution I've been able to come up with is a 'Strategic Warfare' tab (for want of a better name), similar to the Production, Diplomacy or Technology screens. Here, the player would be able to create air groups and submarine flotillas, assign them commanders and aircraft, and give them missions and bases.
Rather than the current method of building a squadron of airplanes or flotilla of submarines, the player would instead build them as escorts and merchantmen currently are. You would order a 'unit' of them, and at the end would be given X amount of individual planes, which rather than being deployed as a unit on the map would go to a pool waiting for assignment, much like merchants and escorts do now.
Here's an example to try and illustrate the system. I'm playing as the UK and the Jerry rotters are being damned unsportsmanlike and trying to bomb me at tea time. Well, I open up the 'Strategic Warfare' tab and decide to create a new air group. I add 40 advanced fighters and 20 basic fighters to the group, using + and - buttons in the same way one assigns escorts or merchantmen to convoys. Then I pick a commander for the group out a list, and an airbase for the group to operate from. In this case, Air Vice Marshall Keith Park can lead the chaps out of Biggin Hill. Once the base and aircraft are picked, I can pick a mission, in this case air scramble, and a region, in this case South East England. With that done, I simply click 'Ok' and the combat is abstracted, over time a series of messages appear telling me that we've knocked down 12 enemy bombers and 5 fighters for the loss of 3 of our own. The content of these messages would be effected by numbers, technology, commanders, radar, etc...
Extra things to consider:
Parameters for the mission - I.e, fly only at night, attack only unescorted merchants, focus attack on fighters, etc...
Limits on aircraft/submarines per airbase/port - I.e, a level 1 airbase can hold 10 aircraft, a level 2 can hold 30, and so on, to stop players stacking every possible aircraft onto a single airbase
Attacks on non-abstracted units - Could be handled by messages similar to those against abstracted units, with non-abstracted units in the mission zone being effected. For example, if the Bismarck runs through the Channel and I have a group of 40 torpedo aircraft set to naval strike, I could get a message telling me that 8 aircraft were lost and that a 70% strength hit was inflicted on the Bismarck, or something to that effect. A similar thing could occur if instead of 40 torpedo aircraft I had a pair of subs operating in the vicinity.
