Confusion perhaps; indecision and lethargy definately.
I am not sure whether we assumed the air unit types were given, but I understand the situation as thus:
Scout Fighter (HOI II: Interceptor)
0 - Early (1915)
1 - Basic (1916)
2 - Improved (1918)
3 - Advanced (1920)
Two-Seat Fighter (HOI II: Fighter)
0 - Basic (1916)
1 - Improved (1918)
2 - Advanced (1920)
Escort Fighter (HOI II: Escort Fighter)
0 - Basic (1916)
1 - Improved (1918)
2 - Advanced (1920)
Recon/Bomber (HOI II: Multi-Role)
0 - Early (1913)
1 - Basic (1915)
2 - Improved (1917)
3 - Advanced (1919)
Contour Bomber (HOI II: Tactical Bomber)
0 - Basic (1917)
1 - Improved (1920)
Strategic Bomber (HOI II: Strategic Bomber)
0 - Basic (1917)
1 - Improved (1919)
2 - Advanced (1921)
Seaplane (HOI II: Naval Bomber)
0 - Basic (1915)
1 - Improved (1917)
2 - Advanced (1919)
Airship (HOI II: Transport)
0 - Primitive (1905)
1 - Early (1915)
2 - Basic (1916)
3 - Improved (1918)
4 - Advanced (1920)
Given this, your .rar download shall be very useful!