I'm disappointed to see the lancaster at the top of the GV killing list.
First, it's not a GV killing list, but a FLAK killing list. In a GV killing list the Lancaster would drop back to rank 6, far behind planes like the A-20, which has twice as many vehicle kills.
Second: The high relative number of Wirbelwind and Ostwind kills results from the way the Lancaster encounters them: By attacking bases (most notably vehicle bases) and towns. Flaks are inbound to flatten the vehicle hangars, half a dozen WW's roll out. The WW at the maproom getting killed by a Lancaster carpet bombing the town.
In AH, Lancasters are actually rarely hunting the battlefield for individual targets like tanks.