So many times in the last five years it has been Smith who has changed the flow of a test by sparking something from a counter attack, or by picking the most simple option and doing it so well and with such authority that the pressure is cranked on the opposition.
Smith knows that not every play has to carry a wow factor and that a failure to balance the portfolio creates the risk of becoming predictable.
McKenzie doesn't yet have that same faith in percentage rugby or the appreciation that a solid hoof deep into enemy territory one minute creates a better element of surprise for running out of trouble the next.
There was one moment in Paris midway through the second half when the All Blacks hadn't had the ball for an age. They needed to get their hands on it, keep it and remind themselves that they were to do something other than tackle.
A loose French kick came McKenzie's way, but with a multitude of options to consider, he opted to chip and chase. It was a poor choice, made worse by a poor execution and the
French had the ball back in a more promising position to the one in which they had given it away seconds earlier.
It immediately brought to memory All Blacks coach Steve Hansen's pre-game assessment of where he felt McKenzie as at with his career progression.
"I have said he is like a fly in the bottle," said Hansen. "But he is getting better at that. He doesn't hit the sides so often. He's managing to go round and round without hitting the sides. He's learning how to play test rugby and test rugby is not like Super Rugby where you can just do audacious things and get away with it because the opposition are a lot sharper and a lot more in tune to making sure their defence is right.
"Whilst we don't want to stop his flair we just have to get him better at the risk and reward concept of what he is trying to do. Like every young test player he's still learning but he is an exciting prospect.
"I think we will see him at 10 next year in Super Rugby and deep down in my own heart of hearts that is where he is going to play most of his rugby."
And Hansen's heart isn't the only one beating in anticipation for McKenzie's positional conversion. The growing realisation is that he's not a fullback, not at this level anyway.
He's doing a sterling job of making it work, but when Smith and Jordie Barrett are both back next year, McKenzie will be the third option.
But almost paradoxically, while the last few months have clarified that McKenzie isn't a test fullback, they have also confirmed, despite his propensity to overplay his hand, that he does belong in the test arena.
He has been able to have significant influence as an attacking force and in nine tests he has done more than many other players have managed in three times the number of games.
His future is maybe one as a bench option, a wild card player the All Blacks can throw into the fray at first-five in the last half hour and tell him to try to make something happen.
They would have to accept the inherent risks that come with McKenzie, but he'd be worth the gamble. He'd be a supremely tempting weapon to carry into tests in that floating capacity: let Smith and Barrett provide the stability and certainty, but have McKenzie as an option to change the dynamic.
It would turn the current scenario on its head as it would be the All Blacks coaches who would be showing that in the relationship between risk and reward it only matters that they and not McKenzie understands it.
Playing McKenzie off the bench as a game breaker would be high risk with potentially high reward.
