I left school in early 1950 @ 14 yrs of age ,did an apprenticeship in the leather-goods trade ,and then changed tack ,got a job in the photographic industry in a laboratory ,which opened up the way for me to be employed in the oil industry as a laboratory technician and officer 34 years until I retired some 12 years ago.
So I have worked 54 years with a 14 years old education as a child.
So I think it all depends on the individual and what they are capable of and not so much there level of education at the time..
We are all different ,some with far less education than me have gone on to be far greater than I could ever hope to achieve in my lifetime.
So i`m not sure that challenging Russells schooling credentials really matters .