In the fragmented world of MMP politics, the trick is to compete and cooperate at roughly the same time.
OPINION: If as a party you don't compete you don't maximise your vote.
But if you don't show you can also co-operate - play nice enough to form a government with at least some of your rivals - you risk the punters deserting in droves.
That dynamic was in play way back in the formative years of MPP, especially during the Labour-Jim Anderton-Alliance split.
The reconciliation between Mr Anderton and Helen Clark that saw her attend his annual conference was a hugely symbolic gesture in the run-up to a change of government in 1999.
So it is now, at both ends of the political spectrum.
The Conservatives are different enough from National to attract a separate demographic - older, more conservative on moral issues and more nationalistic on asset sales and investment.
Close enough, too, to New Zealand First's policy mix to provide an alternative but one that is far more acceptable to National than a party led by Winston Peters. Close enough to NZ First, in many ways, that if it didn't exist there would be every reason for National to invent it.
But no-one is in any doubt that the moral issues can be finessed away in personal votes in the House. Political positioning on asset sales will be more rhetorical than real come the 2014 election and will not stand in the way of a meeting of minds.
On the Left, things are made more complex because the Labour versus Green competition has an echo from a submerged fault line that runs through the Labour caucus.
Labour and the Greens are joined at the hip when it comes to forming a government next year, but just how that is presented to the public is crucial.
From the Greens' point of view the portrayal of a Labour-Green government-in-waiting is optimal.
For Labour, maybe not so much so.
Too close an identification, too much cooperation, and you give your voters licence to support the minor party in full confidence that they will be part of "your" government and you are not undermining it.
That is one strand of the current arm-wrestle going on almost out of the public eye within Labour.
One group, with list MP Shane Jones the most prominent, thinks Labour should draw a clear line in the sand, not only on policy but on how closely the two parties campaign as one administration. It assumes that the parts can be more than the sum of the whole.
Their thinking is that Labour should be gunning for a poll result with a "4" in front of it, leaving coalition options for a later date. It rejects the concept of measuring the Labour-Green bloc's poll rating - be it 45 per cent, 49 per cent or whatever - against National.
Under this scenario, let's call it "the Jones doctrine", Labour does not need to walk cautiously alongside the Greens but can and should boldly disagree. (And, anyway, he would prefer his mate Winston Peters as first cab off the rank in a potential Labour-led government. It's worth noting that his stocks have gone up considerably since his good showing in the leadership "primary".)
How much is too much cuddling up to the Greens, how much is eating their lunch and how much is too much friction with an ally?
That political positioning dovetails with a similar debate within Labour's ranks.
It has bubbled to the surface this week over oil exploration, where Mr Jones has again been prominent, running a much more industry-friendly line than either environment spokesperson Moana Mackey (who has talked in the past of an effective moratorium within the economic zone until stronger protections are in place) or his leader.
But those same divisions were also evident at the Labour conference in Christchurch earlier this month, where divisions over the Trans Pacific Partnership were effectively "kicked down the road".
One group, led by Phil Goff, is strongly in favour of the free trade deal, believing it will bring broad benefits to New Zealand. But there is an equally strong line of thinking in the party that is closer to the Greens' position - that the TPP surrenders too much sovereignty.
Labour has built for itself a halfway house while it awaits details. Meanwhile, it will withhold support until it is clearly shown to be in the broad national interest to sign up.
Labour is also in the midst of an attract-repel debate over the SkyCity casino pokies-for- convention centre deal.
The Greens have taken an unequivocal position. The contract should be ripped up along with any compensation clauses.
Labour has tried to nuance changes to the deal without quite saying it will ride roughshod over the compensation arrangements - although leader David Cunliffe has taken mini-steps in that direction. It is as if Labour is still working through the policy ramifications of this year's leadership change.
How that pans out sets the scene for how much co-operation and competition there will be between Labour and the Greens in election year.