The stats about scenarios tell it all...

Mid war, the Dr1 is more likely to survive than the Camel
Runner vs Dancer, the Spad XIII will win against the Dr1
Runner vs Dancer II, the same Spad XIII will have some hard time against the Pfaltz DIIIa
Here comes the Navy, the Sopwith Triplane will give some hard time to the Albatros DIII.
Etc...

This of course has to be weighted by the pilot's experience and luck

Are too well balanced games really fun ? (Cobra tournament, Yankee doodle, 3^2). May be when played with 4 and more planes, but not really with only 2 (or to give lessons to a rookie ?).