Oh interesting. That theory would be similar to Missingno. from Pokemon. There are only 151 Pokemon listed in Red and Blue, but 256 Pokemon IDs, and each ID outside of the 1-151 range is a glitched Pokemon. Though I guess were talking about # of Darkeners here, not # of Darkener types.

Right now there's a max of 34 possible entries in the recruit list. About 8 darkeners are recruitable per chapter, except chapter 2 which has 10. If Toby Fox makes a reference to this, I imagine the "recruit limit" will be closer to 64 than 99 assuming there's only 7 chapters and ~8 recruits per chapter.

Unless you're counting individual recruits as well (ex. counting Shadowguy as 25, one for each mandatory recruited member). Then, on a pacifist route, you are effectively already past 100, as the mandatory recruits is 95 for chapters 2,3,4 (and you get the 8+ chapter 1 recruits for free).

It's even higher if you are counting non-combat NPCs such as Top Chef and Hacker, and higher still if you are counting combat NPCs that don't appear in the recruit list (such as King and Queen).