The concept sounds slightly more like HOI1. But I don't quite understand the concept of theory and practical yet.
One thing I disliked about the research-systems of both HOI1 and HOI2 was the "back-to-square-one"-concept on all technologies.
Development of an interceptor borrowed noting from the previous development of the fighter.
I would have liked it if, when you develop a gun for your new interceptor, and next month you have to work on a new fighter, you lift the gun-development from the interceptor to the fighter without any (or many) changes. In the game, you built a solid wall between the two projects. I know that the outcome would be much the same - but it'd allow for focusing on different aspects of technology adding flavor.
Say you want to develop a new tank. Several new concepts have to be developed - but the gun is essentially a towed gun mounted in a turret. While the turret may need developing, the gun wouldn't - or if it does, then it'd be quite easy to make a towed gun from the tank-gun, making development of towed guns easier. What I'm getting at is that there's a spill-over of technology. As earlier adressed, militia weapons would not likely have to be developed because they are essentially the same as regular infantry uses - or previous (used) generations of said weapons.
If we imagine a HOI2 type interface, it'd be simulated by having one or more of the the five (six?) tech-bars on each technology entirely or partially developed.
Another example could be warships. You want to develop a new heavy cruiser, well you think innovatively about most aspects of the ship EXCEPT the guns, where you lift the ones used from the (perhaps newly developed) battlecruiser. While not being able to lift them in their entirety due to weight and space requirements, it becomes a question of developing a turret for two, rather than three guns and perhaps a new recoil-brake to compensate for the calibre. This could in HOI2 be represented by the gun-development-bar being partially finished. However, had you not developed a new Battle Cruiser, then the bar would be empty, because you'd need to develop the gun and carriage from scratch.
This was also an issue if you'd neglected to develop strategic bombers early on, yet being a pioneer in tactical bomber development. It was quite unrealistic that once you'd built a fairly advanced tactical jet-bomber, you'd begin your strategic bomber program by developing a two-engined propeller hulk with almost no payload, inferiour to your tactical bomber in every aspect. You'd most likely build an enlarged version of your tac. bomber and slap on twice as many engines. Being given "ancient" techs for free would be the most obvious solution.
But I may be rambling on about a moot point.