Would anybody know who he means by the great historians? Is it classic ones like Herodotus or Thucydides or is it someone more modern?
My guess is the great historians were those in the nineteenth and early twentieth century who tended toward writing gigantic broad narratives that academic historians love to pick apart and prove wrong. But that's a guess, partially derived from this 1985 interview.[2]
[1] https://en.wikipedia.org/wiki/Annales_School [2] https://www.csmonitor.com/1985/0702/dpage-f.html
Gibbon was surely intended as a "Great Historian". And Macaulay (whose "Third Chapter" on the history of the people of England inspired generations of scholars). Maybe Michelet. Prescott. You can still find these all the time in battered Modern Library editions in used book stores.
For my money the greatest historian (who was surely meant) was Jacob Burckhardt, not-quite-incidentally a student of Schopenhauer and friend of Nietzsche. A modern edition will use footnotes to correct claims that turned out to be errors, and you're left with an elegant, sweeping vision of human activity, saturated with all the melancholy and resignation appropriate to the subject.
Two early twentieth century books I've read that probably fit the mold of "great historian" intended by this author are Webb's The Great Plains and Young's Victorian England: Portrait of an Age.
I think what the author means by "old great histories"---as distinct from the many old "scientific" histories that are now merely wrong---is that the historian takes human nature as the primary subject and uses historical fact, at least as best as can be ascertained, as the concrete medium for both exploring and shaping it.
I'd probably add Theodor Mommsen, one of the earliest literature Nobel Prize laureates, for A History Of Rome in 5 books
http://berlin.wolf.ox.ac.uk/published_works/cc/scihist.pdf
But I think in this case he probably has in mind people like the Annales school (mentioned in another comment here) - not so much Fernand Braudel, who wasn't particularly scientific although he was dabbled in economic theories like Kondratiev waves. But more the followers of Braudel who became very focused on crunching numbers relating to land usage patterns, trade, and other socioeconomic data from early modern Europe, to the point that they ended up a bit detached from reality, in much the way that some economists seem to be working in an ideal world rather than a real one. There's also Lawrence Stone who as far back as the 1960s was using mainframes and punch cards to figure out trends relating to the decline of the English aristocracy and the rise of the middle class.
I figured the HN crowd might be interested in what Stone had to say about this, so I looked up an old article of his from the 70s on his methods:
"'the 'new' historians have also borrowed from the social scientrists a series of new techniques...: quantification, conscious theoretical models, explicit definition of terms, and a willingness to deal in abstract ideal types as well as in particular realities. The one new tool they have borrowed is the computer... about 1960 historians suddenly gained free access to this immensely powerful but very obtuse machine, which can produce enormous quantities of data at fabulous speed but only if they are presented to it in limited, often rather artificial, categories, and if the questions are extremely clearly, precisely, and logically framed. Fifteen years of varied experience with the machine has led to a greater appreciation among historians both of its potential uses and its real defects... The computer is a machine in the elementary use of which most professional research historians should henceforth be trained -- a six-week course is ample for the purpose -- but it is one which should only be employed as the choice of last resort. Wherever possible, quantitative historians are well advised to work with smaller samples and to use a hand calculator."