>>>scratchin my head, here. D-Day vs. 1941 ?
D-day was in 1944. Churchill proposed an invasion of Italy in 1941, and did not find it necessary to wait until 1944, when America and Britain launched their D-day invasion.
With what, exactly?
They'd just left ALL of their means to fight (other than manpower) on the beaches at Dunkirk. German UBoats had largely stopped traffic in the Atlantic, as decent convoy / hunter-killer tactics hadn't been invented yet. The US was just barely cranking up war production, and its armies hadn't been significantly blooded. And that's just what I come up with off the top of my head.
Churchill was right. But being right, and being able to prove it, are two different things.