I read it as we've seen what the "senior" guys are capable of, whereas the others have another gear to reach yet.Even feels odd to name Brit in that group but really with over 100 games each they are two of our more senior players.
Who else has played 100+ not named? Ramien is one. BHU and Williams I thought maybe, but both on 99!
So yeah, I guess they are senior players
Nikora probably included as he's now fairly experienced (in number of games + rep experience) and also because he's been killing it.
Brailey... not sure. Given he got the Players' Player medal last year Fitz must be happy with what he's doing.