I think other top 800-1500 guys would have an easier time than Rudisha from the 400 up: Coe, Ovett, Gebrselassie (who has 800 through marathon in his career)--but could any of them even get the B for 100? It seems unlikely. At the other end, what if someone like Ashton Eaton or Curtis Beach started with the 100 and moved gradually up over the four years? I think only the B's are plausible at all.
Anthony Famiglietti had the 1500 through the 10,000--including the steeple, of course--simultaneously in 2008, and when told this, he said (mostly joking) that he should get the 800 and the walks. Clearly he could get the marathon, but he'd probably be stopped below the 800. Still, all these at once, rather than over four years, is a pretty impressive subset of your proposed super-range.