Why a DC-3 gunship needs a permissive air environment

Would an improvised DC-3 gunship have changed the European or Pacific war?

It would have limited effect because enemy fighters would threaten a persistent gunship, even though the concept would suit counterinsurgency.

A DC-3 fitted with spare .50-caliber machine guns would be useful for counterinsurgency. Persistent air support becomes much more vulnerable when enemy fighters can intercept the aircraft. That distinction limits what the improvised gunship would change in the European and Pacific theaters of the Second World War. The comparison with the later Puff the Magic Dragon concept separates persistent support in a low-threat environment from strike support where the air threat is high.