Most importantly, he doesn't come across as nutty, obsessed, and deranged.
In selecting a co-leader, you dilute his impact. And given that, the three candidates we are faced with, is almost certainly a mistake.
I say three, they haven't all declared, but assuming the buzz is right, we have Marama Davidson, Eugenie Sage and Julie Anne Genter. Just the concept of a man/woman rule is archaic. Why not a Pasifika, a Maori, someone LGBT, disabled... how far do you want to take it?
People selected for anything but actual talent and the ability to propel the party forward. Having said that, given I am not a Green, and given this advice will fall on deaf ears, let us turn to the reality of the situation.
If they insist on a co-leader, of the three there is a clear winner: Julie Anne Genter.
Genter, like James Shaw is likeable. I have called her my favourite Green. She didn't like it for fear that my support tainted her prospects within the cloistered world of the tree hugger and snail lover.
But unlike them, I judge people on what they bring to the party, whether I am politically aligned to them or not. She is a genuinely likeable, bright, articulate operator of enough appeal beyond her green mandate to potentially be effective.
Marama Davidson is a radical, not in the executive, and lacks a broad appeal. Eugenie Sage is a classic Green, roman sandals, recycling, and quinoa. Not that there's anything wrong with that, but once again the appeal is limited to those like her.
The Greens need to grow, they need to reach out beyond their 6 per cent of the vote. Beyond their save the whale brigade and this is the magic of Shaw - he's economically sensible, he's worldly in his view, he's Green plus. If you insist on a co-leader, Genter is the only one of the three, who carries any sort of similar appeal.