A state of some confusion about elusiveness-dependent challenges at Zee

The following 3 options listed the same narrow challenge difficulty (based on either Zeefaring or Monstrous Anatomy).

The current “elusiveness of your quarry” value seems to have identical effects on all 3 as in the logistic function nicely presented. (1) Outflank the (Zee-Beast) [Zeefaring 3 for 50%] (2) Use your hard-won knowledge of monstrous behaviour to predict its movements [MA 3 for 50%] (3) Chum the waters [MA 3 for 50%] But I noticed that immediately after making an initial daring approach (resulted in Pursuit level 6) as a Monster-Hunter, the 3 challenges differed significantly: (1) 20% (2) 40% and (3) 90% for my Monster-Hunter character with Zeefaring 5 and MA 7+1. I just checked the wiki but could not see why (2) and (3) were different since I did not do anything that would reduce the elusiveness (even if I did, isn’t the difficulty a function of the same elusiveness variable?)

From the context my guess is that this pursuit could be made easier by consuming some “Z-baits” by chumming the water. But I have trouble understanding the expected effects in these formulas as currently listed. Will appreciate any clarification. Curious about this mechanics.

The Zee-Beast in my example is the Lorn-Fluke as in May 2024, if that is relevant. I enjoy this “world” event. The timescale feels like “a developing story” at some news outlet like NYTimes.

Also curious about any meaningful difference between “repelling” and “calming” - the latter sounds amicable if that can apply to “Lorn-Fluke” (still no idea what it is if “it” is the right pronoun)