After plenty of thought based on many player's ideas and specifically Capt Trips hand in the WW1 Western Front arena, the best approach for recruiting, training and retaining players would be the implantation of AI training arenas. All are both Offline and FREE online.
1) Ground School Arena
This arena is designed through a tutorial instruction plan for learning how the game works (customize settings, navigating hangar selection, launching aircraft from runway and hangar, manual takeoff, landing, taxiing, rearming etc...).
2) Fighter Weapons School (Top Gun)
This arena is designed for air to air and air to ground training. Enemy AI aircraft, ships and ground vehicles are supplied for players to learn how to attack. Areas can be set apart for specific training (fighter vs fighter, fighter vs bomber, fighter vs ship, fighter vs ground vehicle).
3) Bomber Alley School
This arena is designed for all types of ground target destruction. Enemy AI fighters are supplied for learning bomber defense.
4) Tanker School
This arena is designed for all types of ground vehicles including PT boat. Enemy AI ground vehicles and attack fighters are supplied for players to attack. PT boats get CV fleets and AI fighters.