Umm, split them into 2 groups of 5 headed to the exact same place.

As someone who uses alot of speical forces, i tend to have alot of issues with that first attack. Its rather buggy in that it can do literally no damage. More so against moving targets, tends to start combat but you deal no damage for an hour leaving you vulnerable to airattacks as you lose the stealth. There is another bug, in that if you airdeploy away, the travel time of the helicopter seems to start melee battle with the enemy but they can't deal any damage as your units not there.

So mostly i use them 1 of 2 ways.

First i build up SAS as recon units, ill helicopter deploy as far as i can then proceed on foot, scouting enemy airbases.
(at this stage i don't even launch offensive operations against aircraft as they tend to have alot of defense against ground targets)
Purely a max level drone unit, that is just gathering intelligence.

As the days go by i start building a sizeable force, more importantly i start upgrading them to max to get that increased deployment range. Usally i also build a special forces commander but he can be a hinderance because his deployment range is 400 while max SAS are 500 and getting a max level commander requires level 90 or so.

Then i just roam around as a stack of 10/12 SAS with a commander, no more airdeployment.

Following a successful day of offensive operations, i would then helicopter deploy my SAS units 1 by 1 to defensive poistion to cities to wait out the night. But this has since changed, rebel forces now spawn randomly and not at midnight so this method is void, but before the change, it allowed quick reinforment to attacked cities and quick deployment to nearby hospitals to keep a 10 stack fresh.

But mostly, i tended to stay away from helicopter deployment, and if i did, i would launch wave after wave after wave of 5. Purely because 10 stacks have excessive travel times, and they were backed up with airstrikes, even if it was just fighters.

Don't get me wrong, i use helicopter assaults, but usally it was just 1 unit, attacking rebels, because of the inconsistency with the helicopter assault not dealing any damage on lots of occasions and then locking down my special forces in combat inwhich leave your units defensive, with an offensive timer and your stealth not working. I just found it more viable to attack by land, in excessive force with a special forces commander can push the stack into very high damage against all targets. Literally nothing can stand up to a 12 stack of SAS supported by a high level commander.

Since the commander seems to take excessive damage, you can deploy him to a boat and use docks to increase his regin as he only has 12hitpoints while deployed on water, compared with 45ish on land.

As for normal air assault troops, i tend to use a couple, to capture an island, maybe quick deploy to a large jungle or mountain tile for capture, but they suffer the same inconsistencies as SAS, but without the stealth aspect. So they are sitting ducks on deployment and because of their pathetic movement speed, they are mostly usless in most combat. Usally rebels will slaughter a normal air assault unit due to its offensive nature and lack of defensive stats.

Best thing about SF stack of 10 is they dont suffer the movement penalty of occupied land, so a tank stack with movement of 1 will move 0.66 on an enemy tile, then 1 on allied tile after you capture it, so unless you have a scout rushing ahead, SF actually move alot faster then most common stacks. But yeah, mostly i use them far into enemy line in a large stack going city to city clearing out all defensive units or setting up an ambush on an enemy airfield waiting for reinforments, or aircraft to land. Helicopter deployment is usally for retreat or forward deployment.

Special forces are stealth while helicopter deploying or driving.
They are not stealth while flying in a transport plane, nor in a transport ship. (i may be wrong about transport ship, might be subs that can see them, consider them non stealth in transport ship for now)

As for normal air assault, i do agree you can capture a country quickly, but the macro doesnt work, as in it doesnt wait the desired capture cooldown before redeploying, they act like special forces, rather then capture units (not sticking around to capture tiles). So every hour you have to load up the game, redeploy to another tile, unlike normal infantry where you can just set them on a capture mission and come back a day later. Also if an airfield is taken out, they are sitting ducks.

I tend to just build national guard units, then put them on rush. Because of their low build time, and ability to amass so many so quickly they are much more effective. Air assault are very expensive and use resources id rather spend on submarines, aircraft or others things, i guess i have just airdeployed into large enemy stacks too often to use it as a viable force when you can just airdeploy artillery and bombard a city.

On paper the airdeployment seems great, first hit offensive damage and only taking helicopter defense in return. But in practise, lets just say your putting all your eggs in one basket and there is no retreating if things go sour. Also i believe that AA doesnt trigger until after the deployment timer? i maybe wrong but that deployment timer is so horrable in combat, alot can hapen in an hour and like i said, more then once i have dealt no damage on that initial attack.

... and also naval transport has 10x land unit stack problem too, i hitting this cases, about week ago.

we need new cargo aircraft unit and new dock landing ship (naval ship) unit.