Combat Pilot is going to be a very realistic simulation and so will be very challenging for new pilots. The skills required to fly warbirds take time, training and practice to develop. I suggest that, over time, basic, intermediate and advanced training aircraft be added to the game to ease the transition to more complex high performance models.
Basic Trainer: Gypsy Moth or the Kokusai Ki-86/Kyshu K9W.
Intermediate Trainer: Yokosuka K5Y Type 93 Intermediate Trainer, Ki-10
Advanced Trainer: AT-6 Texan/Harvard, A5M2-K, Mansyu Ki-79 (Ki-27)
Even a few simple training options will help maintain a flow of new players into the game and retain them by reducing the inevitable frustration encountered in learning combat flying.