1 - Spartan-B312When did 7 and 8 come in play?
2 - Carter
3 - Kat
4 - Jun
5 - Emile
6 - Jorge
7 - Thom
8 - Rosenda
Rosenda and Thom were originally going to be part of Noble team early in Halo Reach's development, with the player taking on the role of every Noble team member throughout the game. But Bungie scrapped that because having such a diverse cast seemed to clutter up the story.
Thom was then made to be the previous Noble 6 in The Package trailer where Kat lost her arm. The Noble 6 you play as in Halo Reach is his replacement.
Rosenda-A344 was made to be a background character that you never see but exists in the lore. She is going to be the replacement for Emile should he become "MIA" or if his violent and renegade actions required him to be transferred out of Noble Team.
It would be nice to see Spartan Jun and Rosenda lead a successor to Noble Team in Halo Infinite. Or something like that.