It is cited as one of the major black marks against Steven Joyce which is unfair because there are many more important ones than that.
By the same token Winston Peters' better relationship with Mark Mitchell and Judith Collins has been overrated as a factor. That suggests that Peters' coalition decisions were based on shallow considerations.
The fact is there were strong strategic reasons for New Zealand First to go with Labour, chiefly the greater differentiation and influence that the party would have in a new Government than it would have attaching itself to a fourth National term.
And the fact is that National's relationship with New Zealand First is largely irrelevant.
Peters daily declares National an enemy and there is zero chance of his party being open to a deal with National next time, if New Zealand First actually survives. And if it doesn't, it is not an issue.
Winston Peters will have no choice but to go into the 2020 election as a Coalition partner for the re-election of the Coalition with Labour.
The stability and coherence of the Coalition will take precedence over anything that sets his party at odds with Labour, including promoting previous bread and butter issues such as cutting immigration, highlighting law and order failures and railing against Maori "separatism."
Assuming the Coalition runs full term, the 2020 election will be the first election in which New Zealand First will have to rule out a potential coalition with National.
If the Coalition has done very well, Jacinda Ardern's Labour is more likely to be rewarded and New Zealand First could be a victim of its success.
And if it does badly, both parties will be punished - New Zealand First cleared the 5 per cent threshold by only 2.2 points in 2017 so has little above the waterline.
National's best chance of getting into Government is Labour ending up with no partners next time.
National has already set a strategy for dealing with New Zealand First and, with a few exceptions, it is largely to ignore it.
There is no need for the new National leader to review the strategy or go all out to crush it because that could happen anyway without lifting a finger.
The two leadership contenders likely to be left standing in National's contest remain Simon Bridges and Amy Adams.
One of the more vexing issues for the new leader is not what to do with New Zealand First but what to do with Collins and Joyce.
Collins' future is easier than Joyce's.
She has a bigger future under any outcome after the contest. With law and order and prisons set to become a big issue, Collins experience in that field could be invaluable to distinguishing National from Coalition policy.
She could also draw support to National from New Zealand First.
Alternatively, she could be given portfolios that pit her directly against Ardern.
Collins is also being promoted in some quarters as a deputy to Bridges, instead of Paula Bennett.
While Collins has little support in the caucus for the leadership, some MPs want her undoubted support in the wider party recognized in the outcome.
It would certainly not be a leadership team with an identity problem.
Nonetheless, deputy would be a big call. There are risks in having an ambitious deputy.
But there are risks in having Collins' supporters in the party believing their views have been overlooked.
Whether Collins could execute the same amount of unstinting discipline that English did when he teamed up with his rival John Key is questionable - probably too questionable for the caucus to remove Bennett from the deputy's post.
Whatever the outcome, Collins' standing in the party has been enhanced by the contest.
Joyce is a problem. Because so much power was concentrated in Joyce, John Key, and Bill English, Joyce as the only one left carries a lot of institutional knowledge.
Joyce's greatest value to the party is his expertise in strategy, direction and policy setting, messaging and campaigning.
Despite a few setbacks, he has been involved in some stunning electoral success. Most want him to stay for that – but to impart some of his skills rather than operating as commandant.
Joyce will struggle to keep finance under anyone's leadership unless he delivers an ultimatum that it is both roles or neither. Even then, he would not be assured of finance.
Whether Joyce could stomach staying on in Parliament without the finance portfolio is not known.
He may turn out to be one of those people whose real worth will be appreciated only after he is gone.
