Lord Ripon was indeed a fine shot, but though his total tally may not have been surpassed (his half million plus was not only birds but hares and rabbits as well), the tally for his last 24 full seasons have been surpassed. Sir Joseph Nickerson, from 1966 through 1988 accounted for 188,172 birds, an annual average of 7,841. Ripon's tally from 1899 through 1922 was 187,763 for an annual average of 7,823. For the last three seasons in that period Sir Joe used nothing but 28 bores and for the preceding fourteen seasons used only 20 bores.
Nickerson favored over and unders, matched trios, and on some favored a heavily choked first barrel in order to take the first bird approaching farther out, allowing the follow up shot to also be an incomer, not a crosser or going away shot. His second barrel was lightly choked. I would say this definitely surpasses Ripon, who, as you say used cylinder bore guns.
The better shot a man is, the better he can utilize choke, in an increasing proportion. Whatever Ripon did or did not do with his cylinder bore guns does not validate McIntosh's statement that choke is obsolete, due to today's highly advanced ammunition, IMO.
Stan