NMC
You obviously have little knowledge of modern short range air to air missiles. Have a watch of this video to update your thinking that seems to be based around 1970s/1980s Sidewinder tech:
Also, putting anything like a Stinger onto an Extra 300 would make it handle like a dog (very draggy) and as others have said the puny machine gun you could fit (with significant airframe strengthening required) would further reduce the performance.
Anyone who has done modern fighter affiliation against a tactical mobility aircraft or helicopter knows the real truth. Oddly enough it’s normally only the crews of these aircraft that puff their chests out to say that they are hard to shoot down - some call that living in denial, right up to the point where it happens for real and there is a smoking heap on the ground.