I have a lot of experience with games and gamers. I've been playing Harpoon again for the first time in like 20 years so I've been reading these forums.
It sounds to me that you are sending the search planes out ahead of everything else, like they are SR-71's or something. You need to keep the search planes behind fighters. Especially considering that the AI is almost obsessed with going after your search planes. Without fighters protecting them, the search planes will get shot down.
I also think the other poster suggesting that you be more patient was on to something. In the next scenario you play try this, and remember I have a LOT of experience with games and gamers... The next scenario you play forget about the mission objectives and time limit and just spend the first 3 full hours establishing air superiority. Even if it seems like all the enemy planes are dead, don't do anything for the first 3 hours that is not related to downing enemy planes. Don't launch any strike aircraft, only fighters and air search planes, and just ignore everything but enemy planes for the first 3 hours. Then continue that scenario as if you were just starting. I think doing that will teach you a lot, both the first 3 hours and how different everything is than it normally is for you after that 3 hours.
I actually take advantage of the fact that the AI wants to get the search planes so badly. The EW plane serves a dual role in the air supremacy phase, it detects enemy units and draws their fighters too it like moths to a flame. So use that, position the search plane both where it will detect enemy units AND where you want their fighters to be drawn too. Have the search plane radars on, and the fighters that are protecting it radars should be OFF (that is important). Then defend that area well, because if you don't a fighter you don't see might appear and get the spy plane anyway (you can't win them all).
Finally, when it comes to taking down SAM defenses, keep the phrase "peel the onion" in mind, that will help;-)
I like your tactics...
in fact, I do pretty much the same things - especially in regards to air superiority and "baiting" the AI interceptors with AEW/EW/Recon planes. (The only problem I've had with that is that in a fair number of cases, the AI interceptors can sneak up unseen on the bait planes - despite extensive air radar coverages of mixed types. But, it works a lot of the time - so long as I have enough of my own interceptors around to cover all the stuff the AI throws out).
The situations I've been disussing here may not involve 100% air superiority, but certainly air dominance. Anyway, the destruction of my planes in these cases is almost exclusively at the hands of the hard-to-detect AD units - well, at least, I rarely detect
any signs of aircraft or their AAMs getting after the attackers. As far as I can tell, it's almost always surface stuff that gets 'em.
"Peeling the onion" is the only way I have any sort of success, yet there always seems to come a point where I can't get any closer to the core without extreme losses... mainly because they can shoot my planes but my planes have nothing to target.
By the way, as an aside, I've wondered for a long time whether it is even possible
for the player's side to get hits with bearing-only attacks using SSMs or ASMs. In all the years I've been playing, I don't recall ever
getting a hit while using a bearing-only attack (other than with torpedoes, that is). Back in the early days, I tried messing around a bit with that, using different activation distances, and different types of ordnance, but eventually came to the conclusion that without a solid fix, there was zero chance of even coming close to the target. I always wondered if there was just something
I wasn't doing properly - or if it's just a fact of life that the player needs
a solid fix before shooting.