The main character in each games

I know that in each games the vault hunters are the main characters no matter wich one you choose but in story wise one of them is THE main one out of the four (or 6)

my best friend who know much better than me said (after finishing the games too much time with each characters and listening every echo he found) said to me that his theory, those are the main characters in each games

Bl1 : all 4 (that sound dumb i know but even during the story and in borderlands 2 and after the first one is always the 4 hunters that are mentionned when their talking about the first vault)

Bl2 : maya (there is a lot of echos in bl2 about maya unlike the others like a much more than the others and in bl3 except zero a little bit and krieg in the dlc, maya is the only one that we can really see in the game about the main cast of bl2, even one part of the story turn around her)

Bltps : athena (she narrate the story to maya so obviously she's the main character)

Bl3 : Zane and Amara (comparate to bl2 the 4 vault hunter in this one dont have very much for themself even in echos the only thing that sement that they're the main characters is that they are important in the story of bl4 by helping you)

Bl4 : Vex (my best friend didnt talked to me that much about this one because he didnt liked the game but together we conclude that it was Vex because in the trailers and in game that in a way they show her much more than the 3 others)

Main character in world wise : lilith (she is there in every games, in the third one the story is almost turning around her and in the fourth one she litteraly return even if its not really necessary)