Yeah, I get ya, I get ya. WoB group is actually very open to being slaughtered at the moment; It'd make sense to attack them, yet, I just feel like they ought to have enough time in the IC to at least not have Ritz attempting to kill Layle because she assumes he's a giant being an attention whore.

I'm certain a few villains can, to some extent, find the Warriors of Light without much hassle. Considering that the WoB group is almost entirely magic-based, it'd be safe to assume Kefka can pick up on them with ease; Though he probably has no idea of where Freya or Kain would be, as good examples. 

It might make sense for Mateus to send Marche and some of his Hell Knights towards the Mist Cave Trio then; Or, to make sure he ends up succeeding, to one of the other groups first to get a grasp on his increased power before going after the main objective. If the fight coming up for Freya and Cecil was against a Hell Knight or two and Marche, he'd probably be able to escape alive; Cecil would probably attempt to spare him, considering he's a child. That'd allow him to be pulled back instead of being eliminated. 

Same for the WoB group, honestly. Ritz wouldn't try to out-right kill him; Actually, being a child is probably going to keep him at least somewhat safe from being killed the first time he encounters any of the groups; If he's not simply yanked out by Mateus anyways. So he pretty much gets a free pass, in a sense. Except he's probably not going to tolerate failure from himself, which will get him desperate. And cost him more of his soul to Mateus, because of it.

As for the Hell Knights themselves? I think they work best as seemingly emotionless husks; They simply, for the most part, obey; Perhaps they have their own emotions, but just can't, or won't, express them. Not speaking is another good option; Just pushes the fact they are meant for war, and nothing else. This will also disturb Marche a bit, since he's used to having chummy comrades; It might push his mentality towards Mateus and the others slightly more into the dark.