A.J.P. Taylor & Alan Clark

Points of similarity:

Both are "historians" and each represent the opposite ends of the scale in academic achievement.

Neither specialised in the period in question. Both wrote books about it around the same time with one purpose in mind to make money on the back of the 50th anniversary. Years after his book "The Donkey's" came out Clark was forced to admit in an interview that for his book he had just made things up.

Both books were savaged by peer review by "historians" who were specialists in the period, most notable being Hugh Trevor Roper who had been Alan Clark's history tutor at Oxford.

Neither Taylor or Clark had access to the mass of information that came to light after 1970 which means that anything written by them could not possibly be as detailed, factually accurate or as insightful as work produced by those specialising in the period after 1970.

So if Taylor and Clark are your candidates the Keith A is correct in saying that their work has been largely discredited and their conclusions proven wrong.