Wait, that's how the Animus book FATES work?

[Bombast]

I can't find the exact thread, but the Devs actually did respond to this and said there is a limit to how many fates can appear in a zone, and if you a trying to get a specific fate to appear, clearing other fates in the zone will increase the speed at which your target fate can appear as you are freeing up space.

But that doesn't work, since many of the FATEs needed for Atma books get cleared in less then a minute once started. So even if clearing FATEs speeds up the drop rate (Of which the only proof we have is from SE employees on the forums who don't seem to be actual game devs), doing so almost certainly means you wont get the clear.