From: Tucson, AZ
SAMs historically didn't enter service until the mid-1950s, which corresponds to 1948-49 in E47 terms. But I am incorporating them from the start of the scenario. This means I've had to make some "compromises" with history. The SA-2 Guideline missile is what I'm using as my baseline. That missile has a range of 45km and an operating altitude of 10,000-66,000 feet. I'm dropping the range to 24km (1 hex) and raising the minimum altitude to 20,000+ feet, which makes it high-altitude only. During Vietnam those missiles were deadly. I flew in B-52 bombers in the early 1970s and I know how deadly they were. Even with ever-evolving countermeasures, they were always a serious threat.
Anyway, even scaled down to E47 terms, SAMs will be quite effective. Also, it turns out that AAA gun batteries coordinated with the SAM acquisition radars which improved their capabilities. So, I'm going to leave the heavy and very-heavy AAA guns in the game and give them a marginal high-altitude capability (and also because I have to define 'high-altitude' as 20,000+ feet instead of the 30,000+ feet I originally intended). Heavy AAA guns will still be relatively ineffective because of the jet age, but they won't be completely useless.
How about the hand-held SAM-7? I had a SAM-7 shot at my plane about 02:30 in the morning one night over Cholon Heights, a surburb of Saigon, in September of 1972 and a flare gun saved us [ crew of 13 on an AC-130H Spectre Gunship ]. We were orbiting at about 15,000 and the missile reached our altitude in less than 5 seconds. It hit the spot we were in moments before.
A new theory says that whenever someone discovers what the universe means that the universe instantly changes to something even more mysterious. There is another new theory that says that this has already happened.