Telling apart family-internal developments from contact-induced changes and socio-geographically conditioned areal trends is still one of the main challenges in tracing the development – and stability – of languages. Notably prima facie contact phenomena might turn out to have resulted from the interaction of a variety of sources upon closer inspection; assessing their interaction is a crucial requirement for comprehending the dynamics of change. Based on the example of simplification patterns in the system of short personal pronouns observed in the Balkan Slavic dialects located in the territory of North Macedonian and Greece, the present paper illustrates the necessity of identifying the multiplicity of triggers and their interaction, thereby making a case for the relevance of small-scale, transient patterns in understanding diachronic processes. In particular, it places the simplifications within the pronominal system into the larger context of differential object indexing by preverbal pronominal elements in the Balkan languages. With the loss of agreement distinctions on pronouns being characteristic for the last phase in the emergence of object indexing, both processes appear to be closely related. Obviously, in this case, the convergence of various different processes has created a favorable environment for the mutual reinforcement and stabilization of two otherwise highly volatile phenomena.