Since, the LW had primitive forms of gun counters, and the allied opportunists hadn't developed such "advanced" technology, I'd like it to be realistic

Nah, seriously though, would be nice. Instead of knowing the exact amount, you'd have to use your experience and judgement.
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StSanta
JG54 "Grünherz"
"If you died a stones throw from your wingie; you did no wrong". - Hangtime