He's yet to demonstrate he can run a team, or consistently step up in the pressure situations.
He's good - very good - but needs to become a great.
Although there is an expectation on him to produce magic, it's not actually about that.
The key is making the rights decisions; knowing what the team needs in the big moments, and delivering it.
Johnson has developed well, especially over the last two seasons, but the gulf between his good performances and his average ones is still too great.
Unlike Cooper Cronk or Johnathan Thurston, Johnson's game can still contrast between rocks and diamonds.
His consistency has improved this season, but there is more to come from the franchise's marquee player.
"The Warriors need a controller," said former Kiwis captain Richie Barnett. "Kieran has shown what is possible, though he is a special player that makes everyone around him better and commands the field. It has improved Shaun, and inspired him to lift his game, which he has done."
Having Foran at first receiver has been a game changer for the Warriors.
While he does a lot of the organizing and takes some of the play making load, Johnson is free to roam and inject himself when he sees fit.
It's never really been that way before. Maloney and Johnson had a different dynamic, with the Australian as the senior partner in 2011 before his form fell away the following year.
Leuluai did a good job and brought defensive solidity but always looked more suited to hooker.
Townsend has since proved himself at the battle hardened Sharks outfit, winning a premiership last year but never completely clicked alongside Johnson and behind a less than imposing pack.
"With the talent Shaun has and the way he plays you need a certain type of player beside him," said Barnett. "It doesn't have to be a big name but it needs to be someone with calmness and control about them; someone who doesn't panic."
The last seven years have been frustrating for Warriors fans, with a constant rotation of halves combinations, but it's nothing new for the Auckland club.
Stacey Jones had a huge number of partners during his 261 games, including Greg Alexander, Gene Ngamu, Lance Hohaia, Sione Faumuina, John Simon and Motu Tony.
When Jones moved on after the 2005 season, men such as Nathan Fien, Grant Rovelli, Michael Witt, Brett Seymour and George Gatis filled the play making roles before Johnson arrived in 2011.
