Moyes says:
Paratroopers can't stand up to a major firefight but they excel when harassing lightly defended area, especially those bordering a victory location.
If an enemy has not had time to develop fortifications, or leave behind a worthy garrison, you can drop your paratroopers to quickly turn the point neutral. If you're lucky, you can seize both locations to hand the advantage to your team. Realistically, such easy openings will be rare. Often there will be some type of fortification, or reasonably strong defending unit stationed nearby. This is why you should generally drop your paratroopers into a nearby forest to gain the concealment advantage straight away. This will buy you time to use the artillery strike and still seize the location afterwards.
You can also sneakily deploy your paratroopers into the battlefield's quieter zones, the objective being to overlook enemy troop movements without being discovered. You can achieve this simply by giving the ceasefire command to your paratroopers, who may remain undisturbed for an entire game… as long as your enemy doesn't register their initial arrival.
If you keep a watchful eye, you can then launch tactical air strikes on enemy units as they head towards the frontline. Your own front-line units will have a much easier time, and they might advance so far that they even link up with your paratroopers!