Well, in the Soviet Union during WWII, there were two types of air victories(they didn't use the word 'kill'), personal and shared, or group. In the USAAF, kills would be split up into fractions. I don't know how the Germans or Brits or any other country did it, but they all seemed to grade a solo-effort kill the highest.
So, it really comes down to semantics. It could be called an assist, a group victory, or even some fraction of a kill, but it will still boil down to less points than a full, personal kill.
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129 IAP VVS RKKA