Einzelmission - Single Missions

till now I managed to finish all single missions once I got access. But I get mad with the one called “from all sides/Von alles Seiten”, where you have to defend the Japanese tanks on Peleliu island with a A6M5.

Sometimes, yet after a few seconds, the number of tanks was blasted from 22 to below 10, and latest with the Liberators, the squadron is destroyed.

Anybody with an idea, how this mission can be successfully managed??