Recently appeared is John S. Kloppenborg, “The Didache and the Apostolic Constitutions in the context of association rules” in Joseph Verheyden et al, Texts in contexts: essays on dating and contextualising Christian writings from the second and early third centuries (Leuven: Peeters, 2021).
In essence Kloppenborg argues: “The comparison of the Didache with the bylaws of Greek, Roman, and Judaean associations indicates many commonalities, but some distinctive features as well. It is unexceptional that the Didache’s regulations treated entrance and initiation, the vetting of those who wished to join or interact with the group, meal practices, the general behaviour that should be expected of members, and a keen interest in not falling prey to financial fraud. The selection of leaders – that is, the ἐπίσκοποι – is also unexceptional.”
Cf. “We may thus suggest that if an ancient hearer were to hear a document setting out the conditions for admission to a religious association, describing the means of entry, regulating the manner in which meals are to be conducted, and appointing officers, such an ancient reader would readily recognize an associational lex.” Alistair C. Stewart, “The Didache as an associational lex: re-opening the question of the genre(s) of the church orders” JbAC 62 (2019), 29-49.