But the thing to realise about World Cups is that they come with a unique set of rules and challenges that require the All Blacks to take a different selection approach.
The critical issue is covering for injuries. If a replacement is called in, the injured player originally picked is no longer able to play in the tournament.
The coaches also have to think about game management — how can they win their pool matches, build rhythm and cohesion and not take too much out of key players who may play three knockout games in three weeks.
And also underappreciated is the need to have tactical variation within the squad — individuals with a point of difference.
This is where Ioane comes into his own and far from being a remote possibility to make the squad, he could already be featuring prominently in the coaches' plans, as he is an athlete with the ability to make an impact.
They won't be thinking of him as a starter, but as a 20-30 minute bench player — sent on to get his hands on the ball and do some damage.
Ioane has shown so far in Super Rugby that he's the most damaging ball-carrying loose forward in the country.
Ioane is not a traditional, corner-flagging No 8. He's not a clone, by any means, of Kieran Read, or offering the same close contact work rate of Luke Whitelock.
But far from being a weakness, that is his key strength — a player with the ability to beat defenders one-on-one if allowed to play wider.
The All Blacks don't need duplication in their World Cup squad. They don't need two No 8s who offer the same skill-sets and strengths. They need a wider mix of skills and strengths.
The All Blacks coaches will have already decided they need to see him play a test before the World Cup to get a feel for whether he can replicate his attacking forays at the higher level.
The All Blacks use their No 6 in the wider channels and regardless of what combination of loose forwards are on the field, if Ioane is playing, he'll be used in that roaming role. That's what will be tempting the selectors — the prospect of Ioane coming off the bench in the last quarter of a knockout game and creating something with his pace and power.
Some critics continue to fret about Ioane's defensive frailties but those concerns are exaggerated.
He has dropped his body position and improved his leg drive, and while he will always be viewed more as an attacking player, he's not a defensive liability.
If Read, Ardie Savea and Sam Cane are considered certainties for the World Cup, it might be Liam Squire, Vaea Fifita, Shannon Frizell and Jackson Hemopo are competing for two places.
The likelihood is the All Blacks will opt to take six loose forwards and will need a first choice blindside and a back-up with the ability to start a test and be a bruising, traditional, intimidating No6.
On form, that would be Frizell and Fifita but the return from injury of Squire could change that order.
But it's unlikely all three will be picked, as there's no value in having so many like-for-like players.
Read, Cane, Savea, Fifita, Squire and Frizell wouldn't be the right mix. It wouldn't leave the All Blacks with enough potential variation on their bench.
It also has to be remembered the All Blacks played all three knockout games in 2015 without a specialist lock on the bench.
They had two loose forwards instead and they will be considering that option again. The prospect of using Savea and Ioane will appeal on the hard, fast tracks in Japan.
That doesn't mean the All Blacks will go down that road, but they do want the option available so that once the tournament is in full swing, they can assess how other teams are playing, how referees are interpreting things and what the right selections will be.
It all comes back to balance and selecting a mix of players who open a greater range of possibilities, and there is no doubt that having Ioane in the 31 creates the prospect of the All Blacks being a harder side for the opposition to gauge.
