Collecting Future Histories

In Robert Heinlein's Future History, two short stories, "Coventry" and "Misfit," fall between two novels, "If This Goes On -" and Methuselah's Children. Consequently, Volume III of the Future History has always been Revolt In 2100, containing "If This Goes On -," "Coventry" and "Misfit" whereas Volume IV is just Methuselah's Children.

In Poul Anderson's Technic History as originally published, Volume I was Trader To The Stars (three stories about Nicholas van Rijn), Volume II was The Trouble Twisters  (three stories about David Falkayn) and Volumes III and IV were Satan's World and Mirkheim (two novels about both). However, if the Technic History were to be republished in chronological order of fictional events although not in the seven omnibus volumes of Baen Books' The Technic Civilization Saga, then perhaps we would have:

Volume I, eight stories;

Volume II, The Man Who Counts (van Rijn novel);

Volume III, six stories;

Volume IV, Satan's World -

- but then there are two short stories, "A Little Knowledge" and "Lodestar," between Satan's World and Mirkheim.