For very detailed background on the Palio, see this book from the 70s : La Tierra in Piazza, by Alan Dundes and Alessandro Falassi (Univ. of California Press, 1975). Lots of good photos. Last chapter a sort of anthropological-psychological interpretation, fascinating.
Recently, Allen Bramhall & Gabriel Gudding both discuss (& condemn) agonism & rivalry in American poetryland. Meanwhile I'm using this horserace as a metaphor for it.
Dundes & Falassi analyze the palio as (in part) a male puberty rite, colored by the machismo of Mediterranean culture. Curious & ambiguous symbolisms in the city of the Virgin and the she-wolf (for example, the winning jockey & his clan drink wine and suck on pacifiers after the race). That's just one aspect of it.
I understand & to some extent agree with Allen & Gabriel. Poetry, obviously, is many things at once : an art form, a game, a vocation, a means, an end. Poetry can be (profoundly) a release from egoism and violence and stress and Keats's "irritable reaching after fact & reason".
Sweet music of speech; delightful play & laughter; intellectual bread & wine; wisdom, encouragement, equanimity; etc. etc.
But an artwork also brings into play the faculties of taste & critical judgement. (John Latta quotes Coleridge's description of his reading method as "sieve and winnow" - and shows how it's done.)
Eliot's essay "Tradition and the Individual Talent" is all about coming to terms with contrary forces of ego and ambition, on the one hand, and the objectivity of the art itself on the other. "The progress of an artist is a continual self-sacrifice, a continual extinction of personality."
Critical judgement acts (or should act) as the umpire - fair, disinterested, objective, above the fray. And every authentic poet is also such a judge - both of his or her own work and that of others. In fact this critical activity - as part of the whole creative process - is what makes for companionship, camaraderie & cooperation among fellow artists. It's not just that they are poets together - they are critics together.
When you have a fair referee - then you can have a horserace.
& no one can judge rightly without true love.