Now no one can deny Marvel had huge sucess - but I would argue it was artistically driven in the case of the Kirby/Lee  titles, rather than character driven. 

I think Stan and Jack could have had hits with DC titles if they worked there - without creative restraint, of course.  It was the chemistry between Jack drawing and Stan's writing/editing/vision that made FF more than an assembly of dirivative characters. 

It was Jack's art and Stan's writing that made Thor something more than the retelling of a Norse myth.

But there's really nothing substantial about the Marvel character ensemble that is very original to either men except Spider-Man.