I myself don't believe that those who qualify as Third Positionist accept the political spectrum as a viable thing to begin with.
I don't see the Third Position as an actual extension of the spectrum, but a trite retort by those who gaff at its dichotomy as a genuine current of thought.
Part of this is the incentive to champion yourself as being on one of the ends and chastize anyone who disagrees with you as being on the totally opposite end, or to champion yourself as being in the center (because yeah, only my line of thought cares about being practical, it's not an ideology at all brah) and everyone else as far-x or far-y.
To play the game of the spectrum, however, I will say the following. Distributism would be moderate left and Third Position-leaning. The typically Catholic attitude it ensconces derives its ideal from other than the modernist bias of the conventional spectrum entities. They all talk about being in favor of private property but against capitalism, explaining their heterogenous affinity for small business, craft guilds and workers' cooperatives. They want all the variations of private property without the escalation of businesses into late capitalist conglomerates.
Corporatists, if we are talking about the Italian fascist kind, were sort of the first to claim the Third Positionist label