Just curious about the P-51 FM

[JtD]

You’ll want to explain all that to the men of the 91st, 96th and 100th Bomb Groups, each of which suffered over 400% casualties over Europe from spring 1943 to VE Day (there were 48 bombers in a Group). There were about 20 Heavy Bomb Groups in the 8th AF that suffered a minimum of 200% casualties and several among that number had around 300% casualties. The groups that took the highest casualties lost most of their numbers at a disproportionate rate in 1943...

So, by your standards, these bomb groups were "winning easily" as well. I disagree.

...What the JGs and ZGs in the West prior to the spring of 1944 were doing looked an awful lot like ‘winning easily’ to them...

You shouldn't be selling subjective impressions for fact. In a war of attrition, any side that does a mission every day and comes back with 3% loss will think the other side is winning easily, no matter if the other side loses 5% or 0.5% each day on their own.