Thanks! I mostly agree with your comment about per-dice research efficiency; the only reason I didn’t include additional penalties for triple-stacking your scientists is for the sake of simplicity. If you want to play with a -3 penalty, or (even better) a -4 penalty that rounds up to a -3 penalty if you roll three 1’s, then go right ahead!
Giving each Axis nation 3 tokens and each Allied nation 2 tokens tends to give the Axis an early edge in research (they will manage their first couple of breakthroughs earlier than the Allies will), but then the Allies will start to catch up and then overtake the Axis later in the war, because the Axis scientists (on average) will be more “crowded” and will take more stacking penalties.
You could bump Radar to 14 pts. or even to 16 pts. if you really want to, but there are limited opportunities to make full use of the potential synergy. E.g., suppose Germany is using a “Dark Skies” approach to ward off Allied fleets with its enormous Nazi bomber squadrons. Britain might want both Radar and Anti-Aircraft Cruisers to help protect its fleet. Russia, on the other hand, only needs Radar – they’re not going to build any cruisers. Similarly, Russia doesn’t have much use for Jet Fighters, since if it’s suffering from a strategic bombing campaign, it won’t be able to afford much in the way of extra fighters. There’s also the concern that “Heavy Bombers” has always been an overpowered technology in every version of Axis & Allies that had tech. I tried to err in the opposite direction by making the anti-aircraft techs roughly as powerful as the aircraft-enhancement techs!
There is an “Improved Artillery” tech in some of the OOB versions of Axis & Allies, and I’ve never seen anyone buy it, except maybe Russia, who really does have to count every dollar and might not be able to afford enough artillery to fully power its infantry stacks. It is really challenging to fully exploit the advantage of 2:1 artillery support is that it’s really hard to maintain the desired ratio. E.g. if I have a stack of 10 infantry and 5 artillery, then after one round of combat, I probably have something like 2 infantry and 5 artillery, and the extra artillery support becomes moot. It stays moot on defense, too, when those artillery try to hold the ground they just captured. But if I have a stack of 20 infantry and 5 artillery instead, then my army is hugely inefficient – even with 2:1 artillery support, I’m only generating 40 pips of punch on 25 units, so I’m going to give you multiple rounds of combat in which to score hits and wear down my army.
You get the same problem in reverse if you want to only boost the artillery’s native attack power. With a stack of, e.g., 8 infantry and 3 artillery, the tech would only give you +3 pips of punch – it’s just not very exciting. You could try attacking with a stack of all artillery, e.g., 10 artillery for $40, but that just seems weird and un-thematic.
Anyway, let me know if you try out the rules, with or without some modifications! I’d be curious to see how they work in live play. I’m defending my rules so you have the benefit of my opinions, but they’re just opinions, and ultimately the house rules are there for everyone to enjoy however they like…if you think you’ll have more fun tweaking the costs or nerfing a couple of the techs, then go with what seems fun! 🙂