Having Bové in formally might encourage them to drop out. Voynet (because the Greens are currently inaudible and ridiculous given the favorable context) and Besancenot (becasue he was open to the idea) are possibles, and Buffet might be convinced (also to avid an humiliating flop). They all agree that there is a need for a single alt-left candidate, but they all want to be it. Bové has more popular appeal, and probably more legitimacy outside of the "apparatuses" - but as you point out, they do matter.
Who does get the 500 signatures will matter a lot.
(Laguiller is outside of al this, I agree, but she will lose votes if there is a superior - i.e. unique - alternative on the hard left) In the long run, we're all dead. John Maynard Keynes
The problem for Buffet and Besancenot (Buffet et Bontemps mean anything to you?) is precisely their respective apparatus, it seems to me. A split in the PCF is really possible if she stands down. And she doesn't have a signature problem.
Whereas Besancenot... does have a signature problem, and probably less hard opposition within le Ligue to his standing down.
Bové's candidature does, I agree, have that logic. He's out to get at least Besancenot to quit.
As for activists, that bleeding has been going on for quite some time. Probably too much cooperation with the PS, especially the way the PS was in the '90's.
Imho would have been wiser to play it safe and sit this one out like in '74 and concentrate on rebuilding at the cantonal and regional level. Might've earned some credit by backing one of the anti-liberal candidates (though seems to me Bove was a bit too coy for a bit too long, and, well, Arlette is Arlette, fun to watch in action but seriously...) and grown the activist base, or at least the loyalty of many anti-liberal activists.
Oh well, she can't do worse than Hue. Not that that means anything - by not running, she would have of course done better. Fai de bčn a Bertrand, te lou rendra en cagant
I think Bové didn't accept the conditions he would have had to for Buffet to get the Party to agree. As for Arlette, afaik there was never any question of her being the single candidate. She announced long before anyone else that she was LO's candidate and that was that.
I expect Buffet will go ahead rather than break the apparatus. Besancenot... Suppose he can't get his signatures and Bové can't get his either... There'd surely be support at the LCR for pooling sigs on Bové's name...
Probably will do so in future if you don't first, but only if anything changes. All the polling numbers are pretty low for hte LO, PCF and LCR, we'll see what Bove's entry does but my guess is not much. Fai de bčn a Bertrand, te lou rendra en cagant