Some languages display 'agreement displacement' (Béjar & Rezac 2009): the phenomenon in which features from multiple arguments compete for realization in a single morphological slot. A prototypical example comes from Georgian and other South Caucasian languages. In this family, there are systematic blocking relationships between subject and object proclitics, ensuring that only one clitic appears on a verb. I advance an analysis of the South Caucasian facts rooted in cross-derivational competition. The Principle of Minimal Compliance (Richards 1998) admits derivations that only involve subject cliticization, or only object cliticization. Independently motivated post-syntactic constraints filter out the derivations with sub-optimal morphological properties (Foley 2017). This approach is more economical than an alternative in which both argument cliticize, and one is deleted post-syntactically (Halle & Marantz 1993), it is empirically superior to an analysis which derives agreement displacement from purely syntactic mechanisms (Béjar & Rezac 2009).