Collins' first priority will not be to unify the caucus. It will be to lay down the law in demanding discipline.
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She needs to insist not a minute be wasted on sheeting home the blame for what happened to Todd Muller.
It has already proved too strong a temptation for some, as the finger is pointed at former deputy Nikki Kaye and No 3 Amy Adams for being too influential over the inexperienced Muller.
But that needs to stop.
From National's perspective, that debate can be delayed for another day.
The chances are National will have three more years in Opposition, with plenty of time to debate whose fault it was that Muller failed.
It is to be hoped Muller himself gets to write his version of his brief time at the top, and what led to his decision he was not up to the job.
The election of Collins to replace him is the best decision the caucus could have made in the circumstances, and the one most likely to draw a firm line under the unfortunate past.
Her profile and brand is already so strong that any other selection would have been instantly problematic.
Gerry Brownlee is a good choice as deputy. Together, they will present a sense of stability in the leadership team so desperately needed now for the party.
His role as campaign director will also be invaluable.
Collins' experience showed through in the press conference and when asked what the major difference was between her and Prime Minister Jacinda Ardern, she said "experience".
She spoke compassionately about Todd Muller and first-term MP Hamish Walker, who was forced to resign last week, but equally sympathetically about the Covid-19 patients whose details he passed on to the news media.
Collins and Brownlee will have a reshuffle to organise.
Michael Woodhouse will be lucky to keep Health after last week. But the reshuffle should not take long.
The caucus should not need to be handed favours in order to mollify and unify it.
If it has not already been jolted into a sense of unity through the shared adversity of Muller's demise, then nothing will save them.