Düttmann had a MK108 in his Bf, no 37mm
Anyway, if the tank has some additional fuel stored on its back, it is easily possible even with a MG.
For example Rudel claimed a dozen or so tanks in one mission with Ju87D, when broken through T-34 had additional fuel stored on their back.
About other units: I never heard that tanks were counted in the same category as planes. But Schlachtflieger had claimlists for tanks and planes, so why not do the same for Jagdflieger?