As I mentioned give each country a Air Transport plane on setup at there Capital only.
You can promote 1 Inf to a Paratrooper (cost 2) per turn only for starters.
You can buy more Air Transports if you want.
Air Transports C10 M4-5 FAB AD0 Can take as a Casualty.
Paratrooper C2 A2 first round only. Then A1 D2 Art +1 on A
or go with IL’s idea with no Art boost or support.
Paratrooper A3 first round, A2 second round and then A1 rest of rounds. D2
Start with something and test play and tweak as you go on.
We use Paratroopers and Elites in my game and there being used by all countries.
Malta, Norway, Crete, Pacific Islands, Dutch Islands, can openers and blocker landings.
Also Air Transports can transport 2 Para or Elites.
But I would keep it to 1 if you think 2 is to strong for Germany.
At least with 2 you have a better chance (some support helps) to take and control an Island.