Well, I would say that not caring about telling the truth at all (group #2) can be considered sistematically lying - they do know they're lying, they just don't care at all about something they say being true or it being false. Their intent is to convince others no matter how and if that requires deceit, outright lying is an absolutelly normal and commonly used tool in the toolbox they use for it.

It's not "intent to deceit" in a sort of per-lie way as a normal person would have - i.e. a child denying they got a cookie from the cookie jar by blaming the dog - but a far broader "intent to deceit" that's not limited to that one lie - i.e. constantly spinning stories and manging the impression and images one projects, using outright lies just as easilly as using half-truths or selective information: the whole structure is deceit. This is mainly how they differ from normal people, who are not casual users of lying when they intent to deceive hence use lies in a more purposeful way (as they have to first convince themselves to lie).

The only real difference between the likes of Trump and most mainstream politicians (such as Biden) on this is that the threshold for using lies whilst doing their story spinning and image management is a lot lower for Trump (who just straightforward lies a lot), but those using sleazy language, selective information and other forms of inducing others to reach false conclusions still have an intent to deceive even if they avoid easilly spotted lies.

I do agree that those in the third group are indeed not lying, which is why I separated them from the other 2 groups. They're not trying to deceive (hence why they react so badly when accuse of doing so) even though they are deceiving, though the "lying" in their case is done first to themselves by chosing to refrain from examinining certain things they are told.

I think the easiest to understand here are religious people: they trully believe the unproven and unprovable, mainly because they chose to not check any of it for believability - the ones amongst them who present something as as being "information" rather than "hearsay", even though they purposefully chose not to evaluate it are they ones lying, not because they knowingly are telling untruths, but because they're lying about the "informational" quality of what they're saying. (So, for exampl, somebody saying "The Bible says: X" are not lying, but the ones saying "It's X" are, not on the "X", but on the use of "is" rather than telling us they got that "truth" of their from a religious book).