Ringworld Timeline Discrepancy [Fate of Worlds Spoilers]

[Anushka Mokosh]

Okay, so here is the thing. From the original tetralogy, Nessus was given mating rights in return for proceeding with the first Ringworld mission which we find out in the Ringworld book. The mating was to happen with the Hindmost of that time. In Fate of Worlds, we find on that Baedeker was Nessus' partner. However, that doesn't fit with the timeline provided in Fate of Worlds or facts mentioned in earlier books as well as the character listing in Fate of Worlds.

First Ringworld mission happens after Achilles under Ol'tr'o, takes over the Hindmost position meaning he'd have to be the one who promised partnership to Nessus. Yet, in second Ringworld mission, the "Hindmost" who kidnaps Louis and Chumee was Nike (information from Fate of Worlds character listing) who is the same Hindmost Louis and Chumee meet in Ringworld and who did in fact mention mating with Nessus in Ringworld Engineers.

I did not finish Fate of Worlds yet, but this has been bugging me greatly since I can't make much sense to it. Can anyone explain or at least tell me if it gets explained? I don't mind spoilers because this is really bugging me. Should clarify that I've only read Niven's Ringworld tetralogy and am at the last book of Niven & Lerner series.