So when was Fangio at his peak? Many would say 1957, although you seemed to be suggesting somewhat earlier than that, by which you must mean the 1949/51 timeframe which I can see as valid - hence my comment both were similar distances away from their peak. I was playing devil's advocate in Fangio's favour on that point.
Pure age arguments are hopeless because Fangio only really came to world prominence in 1949 (age 38), whilst Moss' frontline career ended age 32. But I wouldn't try to argue that to fairly compare the two we should therefore ignore everything Fangio achieved after age 32 (which would be virtually everything). It's just that different drivers have different career arcs, that's all. Nuvolari is another one, almost all of his great drives were in his late 30s or 40s, having primarily done motorcycle racing for most of the 1920s.
Completely agree with you here to be honest - but if I was going to take a stab at it I would presume that Fangio would have lost a touch of speed (quite a lot probably), but would have seen it all before, while Moss would have been very close to his peak pure speed wise but without Fangio's experience, by the time they were up against each other at the highest level.
Sadly Fangio's best years were very likely wasted by the war, which makes the fact he held the record for most WDCs for over 40 years absolutely astonishing.
