Good options all, but the one that appeals the most is the elevation of Cane. That's not just a long-term view based on the value the All Blacks have previously had in anointing a successor early, as they did with McCaw when Tana Umaga was captain, and Read after McCaw had taken over.
Read captained the side nine times between 2012 and 2015, experience he says was vital in helping him in 2016 when he took over the job full-time.
So if Cane has been identified as the most likely choice to inherit the captaincy when Read retires - probably after the 2019 World Cup - it makes sense to invest in him now.
Captaincy is a long game. No one cracks it earlier and it's week by week that leaders grow, as proven by McCaw, who was a vastly different - better - captain in 2015 than when he began in 2006.
But Cane's credentials are equally compelling, even if the long-term future is not considered. He has come of age this season as both player and captain, and his leadership of the Chiefs has been extraordinarily good. Judge him against Smith and Whitelock and how they have respectively led the Highlanders and Crusaders, and he comes out ahead.
The Chiefs had to deal with a horrendous injury toll in the first five rounds that saw them head into battle as a collection of bit parts bound only by the mastery of Cane's supreme commitment and will to win.
They had no business escaping from Eden Park with a victory in round three and yet they did, because somehow Cane's phenomenal energy, defensive crunch and ability to miraculously steal possession, inspired his thrown-together side.
It was McCaw-esque, captaincy by example. Fearless, relentless, follow me stuff that hinted Cane wasn't subject to the same laws of physics as everyone else.
It was in the return game against the Blues, though, where Cane staked his claim to the captaincy throne. His maturity came to the fore. For the first 32 minutes of the second half, the Chiefs pressed. They were two points behind but the Blues were the weeble that would wobble but not fall over.
The rugby gods appeared to be conspiring against the Chiefs; they dominated possession and were permanently camped in the Blues half but some puzzling refereeing and poor execution left them battling a rising tide of frustration.
They could so easily have lost their focus but Cane took control, exuding only calm and patience. His body language gave only a sense of determination to overcome and he instilled in those around him a refusal to believe they were victims of some kind of injustice.
Each time the Chiefs were thwarted, Cane would gather the team and persuade them to stay patient because the big break would eventually come.
Which it did, and when the Chiefs were finally awarded their match-winning penalty try, it was more to do with the skipper's brain than the pack's brawn.
"Frustration can creep in, but you can't allow it do dominate your thoughts," Cane said. "Otherwise it just dominates and affects the way you play the rest of the game. There was a bit of frustration that we were creating opportunities, not finishing them off.
"It felt like sometimes we weren't getting the calls we really wanted. So a couple of times, we just brought the key decision-makers in and said, 'let's not get frustrated, let's just stick at it. We'll get our crack and we'll make the most of it when we do'."
A lesser captain wouldn't have steered the ship home and that 21-19 win for the Chiefs was the moment for the doubters to change sides and admit they were wrong.
There is no other openside in world rugby who tackles with the same intensity or regularity. No seven is carrying the ball with similar impact and Cane, perhaps as a result of his increased confidence and physical presence, has become the sort of ball poacher opponents hate because he tends to pull them off at such critical times.
There is one other factor that strengthens Cane's case to captain the All Blacks in June - he's likely to be the senior representative in the back row and therefore likely to play 80 minutes in all three tests.
It was the probability that he wouldn't play 80 minutes in the final test of last year that led to Whitelock being given the captaincy against Wales.
If Read doesn't make it, the All Blacks are going to have to turn to an inexperienced No 8 such as Akira Ioane, Jordan Taufua or Luke Whitelock, or they will have to ask Liam Squire to shift from blindside, paving the way for a relatively inexperienced No 6 to come in.
Either way, Cane will be the senior figure and the coaching team will want him on the field for as long as possible and that should clinch his captaincy in the increasingly likely event of Read not being involved.
