Your both wrong, looking at the code, the 109 and the corsair weigh exactly the same. The drag on the 109 is about twice that of the corsair (0.105 vs. 0.0652). The inertia on the 109 is set to 1/1/1 and on the corsair to 1.05/0.850/0.94 (in terms of x/y/z, forward/backward being x) So the corsair has more tendency continue in a straight line. The engines are at the exact same settings. Wheel strength and damping are the same. Both bodies have the same lift (2). The wing lift on the tail is the same for both, but the corsairs rear flap lift is greater (0.5 vs. 0.35). The 109 has the corsair beat with main wing lift and flap lift(2 and 2 vs 1.85 and 1.7) and the elevator (Rudder)(the rear flap that sticks up) on the corsair has a lift of 1.0 and the 109 has a lift of 1.5.
So looking at the planes, it depends on what your doing, the corsair has less of a tendency to stall and is faster, (less drag, same engine) but is not able to lift or maneuver as easily. Maneuverability being based on the greater forward inertia and the elevator lift.