Devil's Sting requires Krill, has a !! bite but bites much later than Titanshell Crab or Mistbeard's Cup. Flaming Eel is a !! bite whose bite time overlaps with it but it is not available when Devil's Sting is. Flaming Eel is Sunset, Devil's Sting is Day.
This table is showing accurate macro-based timings:

The blue highlights are what the fish is most likely to bite on (or the required one, not account for Versatile Lure), the green ones mean the fish can bite on that bait but they have lower bite rates.
On any ocean fishing bait: Titanshell Crab is an "instant" bite which displays as 2-3s, stopping exactly as your macro timer hits 3s and Mistbeard's Cup is 3-4s, but won't bite exactly when your macro hits 3s. Devil's Sting starts biting much, much later and does not overlap with them in any way.
The example with Titanshell and Mistbeard's Cup's timings is a good example for most of the low-point high-yield DHx4/THx7 fish and how they can be blind THed, but it might appear difficult (but in practice is not really). But, in text this difference is both difficult to explain properly and so is difficult for novices to grasp, so I would agree that trying to get this across in a guide aimed at novices is not worth going into detail on and keeping it to the easy one of Jetborne Manta is appropriate but it can bite using Krill too.
Devil's Sting bites so much later and has both a higher point value and better bite rate so I think this is worth mentioning. However, if going to continue to use Lulu's timings and/or not explaining theat at face value they don't express how they can be blind TH/DHed, the Callichthyid recommendation is the second version of "easier" stated above, so is sound if that is the approach being taken, but brought it up to highlight that Devil's Sting is flat-out better and also still very easy.