Much of the brawl about D’Hondt isn’t really about D’Hondt. What it’s really about, it seems to me, is the relative importance of an SNP majority vs the maximum number of pro-independence MSPs.

For the uninitiated (and if you’re familiar with all of this, skip this bit) I’ll try to summarise: Scotland’s voting system gives each of us two ballots: one for a constituency MSP, one for a regional party list. Once constituency MSPs have been elected First Past the Post, the list votes are used to try to balance out the parliament, making the total number of seats each party has in each region roughly proportional to the vote it gets on the list ballot. To do this, the number of votes a party gets on the list is divided by the number of MSPs it already has in the region (including constituency MSPs), plus one.

The quirks of this system have led some to argue that supporters of independence ought to use their list vote to back a “Yes” party other than the SNP. After all, each SNP vote will be divided by the number of seats the party already has in the region – which is likely to include all or almost all of the constituencies. A vote for a party which isn’t going to win constituencies has more power.

Others point out that such a tactical vote could cost the SNP MSPs – after-all, they managed to win every constituency in the North East in 2011, and still get a seat on the list. Particularly in the case of RISE and Solidarity, they point out that tactically voting for a party which is yet to register any support in the polls is a fool’s errand. A huge SNP vote may still be bigger than the RISE vote even after it’s been divided by ten. It doesn’t make sense to vote tactically for a party which has almost no chance of winning. It’s a circular argument, but to make the case for tactical votes, RISE do first have to show that they have a chance of getting in.

For me, though, this whole stooshie obscures a very different question. As often seems to happen in politics all across Britain, an argument about maths is hiding a debate about politics. Because, ultimately, both sides are failing to admit to some basic things.

First, it really is true that a relatively small proportion of people who support independence voting Green rather than SNP on the list could notably increase the overall number of yes supporting MSPs (and so decease the number of unionist MSPs). Even the worst polls for the Greens shows the party in the proximity of getting an MSP in each region, so a Green vote can hardly be dismissed as wasted. It’s also true that, in the process, a few people who would become SNP MSPs had those voters backed Sturgeon’s party, might well miss out.

To get a sense of the sort of difference this can make, it’s worth spending some time popping recent polls into one of the Holyrood seat calculators, and then shifting votes between the SNP and Green boxes on the list. The differences aren’t huge, but they are meaningful. For example, the most recent poll, as I write this, gives the SNP 70 seats and the Greens 8. If two percent of people shift from the SNP to the Greens on the list, then the SNP keep 70 MSPs, but the Greens go up to 12. If five percent switch (which is probably fanciful), then the SNP drop 1 MSP to 69 seats, the Greens rise to 16.

If the SNP have a particularly bad day (compared to the polling and their recent electoral performances) such a vote might even narrowly cost them their majority. On the other hand, if such a switch was on a big enough scale to make that kind of difference, it would also very likely increase the total number of independence supporting MSPs, and reduce the number of unionists.

The question, then, is, which of those things is more important for those for whom independence is a primary concern? In both scenarios, Nicola Sturgeon would stay as First Minister. In both scenarios, Holyrood would have a majority of MSPs who support independence.

I have been asking for a while: why is it so vital that the SNP get a majority, rather than simply an overwhelming plurality, with Sturgeon reliant on support from parties to her left? I’ve yet to hear a good answer.

Looking at the long term question of independence on its own, it seems to me that a parliament made up of a number of different parties, arguing passionately on other subjects, but agreeing on independence, is more likely to convince the majority of Scots to vote Yes next time than a more monochrome chamber seen to speak largely with the same voice.

It’s not by supporting the SNP until independence that we’ll convince our fellow Scots of the case for it. It’s by building in Scotland an appealing, lively and hopeful debate about the future which excites people much more than the moribund drone of Westminster. After-all, neoliberalism didn’t conquer the UK by capturing the Tories. It won when the debate became one between a number of different parties, all of whom agreed on the basics of privatisation, deregulation and trickle-down economics.

More generally, on issues from land reform to local taxation, energy policy to economic strategy, Holyrood is more likely to thrive if the SNP is kept on its toes; if other parties are able to push forward more radical ideas and to keep debate alive.

And, long term, that’s probably what’s best for the SNP too. Its own growing domination is perhaps the biggest long-term threat that the party faces. It’s not because of any intrinsic laziness or corruption or idiocy that Scottish Labour became what it did. It’s because strength bred complacency, attracted the sorts of people attracted to power, and stopped the flow of new ideas.

Those who argue that voting ‘tactically’ for parties other than the SNP is too risky are afraid that, on the most pessimistic reading of polls, the SNP might just lose their majority. If you think an SNP majority is vital to Scotland’s future – that the party leading a minority government sometimes dependent on Greens and perhaps others would be a disaster – then it certainly does make sense to vote SNP with both votes. If you are a loyal SNP supporter, you’re presumably going to vote SNP as a matter of principle, and who can argue with that?

But if you’re the kind of person who wants Scottish politics to be bolder than that, then don’t let anyone tell you that voting for someone other than the SNP is too much of a risk. The biggest danger in Scottish politics right now is that we let the SNP slide gradually into the comfortable bum-print Labour left for them in the seat of power. In May, we have a great opportunity to vote for a vibrant parliament representing the best of the Yes campaign. Let’s not miss it.