Posts like these make me continue to read here even though I so often contemplate stopping because of the distressing signal to noise ratio.
How do you treat those who's momentum of success was clearly interrupted by tragedy? I'm not referring to Pironi or Villeneuve either. They had not yet really achieved great success, though Villeneuve won the hearts of many. I'm more referring to Senna and Clark.
As far as drivers who died on the race track is concerned, for me, the simplest answer is the right one : You simply cannot extrapolate results of a drivers career into the future, as they are most likely wrong. The most recent example of this is Schumacher's failed comeback, anyone who has watched the sport for a while would have thought that a highly successful combination of Brawn and Schumacher in a WDC winning team, would have atleast been able to pull off a win or two, or atleast a few more podiums in these 3 years. It did not happen.
Past success is not a guarantee of the future. It may be a reasonable assumption, but never one which is conclusive. As far as Jimmy Clark, Ayrton Senna or even GV is concerned, their careers ended the day they died. End of. There will always be, atleast two interpretations of how their careers would have played out if they were alive, both of which will always be reasonable because it cannot be proven.
Fangio's equipment advantage is largely a myth. No doubt the Alfetta had the legs in 1950, but in 1953 he was the only non-Ferrari winner in the F2 World Championship, he drove an ageing 250F in common with half the field in 1957 and still beat them all hollow, and the fastest thing about the Merc in 1954 was Fangio. Back then it was possible for someone to buy the exact same car as the world champ had. I don't think that sort of affair has happened since 1960.
You missed the point I was trying to make, which is its easy to explain away success in Formula 1, if you want to. Every racing driver has a lot of factors behind his success, apart from his own talent. The debate will go on forever and you will never have any answers to it.
I can see you are trying to sidestep the issue of equipment dominance Fangio had, but its false. He drove the all conquering Alfettas for two of his world championships, '50 and '51. Also your point about his tenure in Mercedes is highly contentious, as in 1954, after the new Mercedes was introduced, it was quite simply the best car on track. Thats 3 of his WDCs in easily dominant cars.
There's no need for a world champ. There isn't one in golf or tennis. It gives a narrative to the season, true enough; it also provides an artificial climax for people to be captivated. But it does nothing to determine who the best driver is.
Drivers may drive for the title. But that doesn't make them the greatest ever.
For me, this represents an irrational widening of the pool of candidates for the "greatest ever" driver. If the very standards by which success is recognized in a sport is to be shunned, then we'd be left with over a hundred candidates for this debate and no answers. You could pick up a random Olivier Panis, Jody Schekter, Nick Heidfeld (and for the more creative among us, drivers even lower down in the food chain who have driven for the likes of Minardi ) and make a case for them to be considered as the greatest of all time.