Now over to some hopefully constructive criticism and questions, some criticism might just me being a newb...

I have ONLY been playing the game for about a day... but a that is nearly 20 hours or so...

I do get the feeling that the AI is kind of gimped in the air war and if you babysit your aircraft you can whoop the AI without much effort. The air mission planner is inadequate in a few ways.
1. AI don't understand how to support their aircraft with numbers or fly in proper squadrons or at least with a wingman. I never fly my planes solo and can overwhelm the AI with local superiority most of the time because of it.
2. You can't use the mission functionality to patrol areas, the AI (as above) never support their assets and just go in for the brawl, which result in unrealistic loss of aircraft. If you have a range advantage there is no reason to risk your planes in close combat. Likewise if the enemy has a range advantage, you need numbers. There are no point in wasting your planes unless there is a bigger issue to consider.
The scenario I played were mainly about air warfare so I have only touched the naval stuff, but there don't seem to be the same problem with naval stuff since the AI seem generally well designed to handle their SAG, CAG or whatever their formation is.
In the scenario that I played I first used the mission planer to set up patrols for my aircraft which just resulted in them getting a huge casualties rate. When I restarted the scenario I handled them manually and did everything I could to stay out of range and save my planes. Since the AI rarely supported their aircraft (or tried to bait me) I could often destroy them in piecemeal. I only had to fire my weapon, return to refuel and rearm and do it all over again. As long as you have a few hours or a day or two it works very well.
I then opted to play both sides, this was a scenario only optimised for play on one side so I decided I should use the resources in a way the scenario was set up, otherwise it would crush the side I originally played in no time.
The result now was more realistic, the air-war became more drawn out both timing and losses on both sides seemed more natural even if the original side eventually prevailed as before.
I feel that the AI and mission logic must learn to understand when to engage and with what weapons. I don't want to engage a MIG-29 with Sidewinders after I spent my AMRAM unless there were a very good reason to do so. If the MIG survive I rather turn back to rearm and have my second wave take care if him.
The same goes for easy prey, I don't want to waste my AMRAMS on a ground bomber or helicopter if they can't fire back at me. Sidewinders or other similar missiles work just fine, that way I can stay up and engage real fighters as well.
The AI must also need to understand that it many times are wiser to just waste ammunition to get the kill if there are no room to fall back and go at it again. Just run up, fire all your long range missiles at a few targets and get out. Head back to base to refuel, rearm and back up again. The AI obviously need to take ammunition storage at the base in consideration, but for the most part it is better to have a sure bet to kill the opponent than risk them being able to shoot back at you.
I'm pretty sure that real pilots are using the same logic when engaging an enemy. They might know from experience or simulation how often a certain type of fighter are able to dodge incoming missiles. Better to make sure and fire a few extra and just retreat if there otherwise is a risk someone on your side will be shot down.
It will obviously be different if you are on the other side and have range against you, now it is even more important to use supportive aircraft and tactics such as cutting of the retreat of the enemy so at least a part of your force will get to fire their missiles. The AI should be thought how to do that when they are technologically inferior they need to rely more on numbers or at least local superiority.
In any way... I find the mission planer very inadequate to use for anything but submarines and navy ships. Some missions can be done where the weapon load-out are homogeneous and all planes run in one single large group. Then it works pretty good.
The arbitrary number of 1/3 assets in their air at once is not a good way to solve rotating forces. They must be more flexible. Sometimes keeping 1/3 forces will destroy you, while it might be enough at times. The AI must be ably to decide to overrule this and send up more reinforcement (but not just all or nothing) if they see that the enemy is increasing their activity.
Planes should also be launched on groups, squadrons or wings... whatever make more sense given the number of aircraft operating in the area.
There also are very bad support for land combat unit in scenarios where there are some land combat. I also find that land combat is too fast and brutal. It should be tweaked so land combat mostly bog down into stalemates and become drawn out. That is kind of realistic, units usually don't have clean shoot-outs without one side being forced to retreat and/or dig in.
Combat in the game can usually destroy large forces in like half a minute, at the very most a few minutes.
Anyway, some of my thoughts after playing almost a full day with the game.