The grammars of some languages include two or more number subsystems that function in different morphosyntactic contexts. These subsystems may vary in the number of distinct number values distinguished, or in other ways such as obligatoriness. Such 'mixed' systems (Dixon, 2012:52) have been little-investigated. Corbett (2000:89-94, 120-121) analyzes them solely in terms of the nominal Animacy Hierarchy (Smith-Stark, 1974; Silverstein, 1976; Comrie, 1989:128; Corbett, 2000:56), asserting that in such languages, the number subsystem with the most number values should always function at the top of the Animacy Hierarchy (2000:92). A further assumption of the Animacy Hierarchy is that splits between number subsystems should fall between adjacent entries on the Animacy Hierarchy. This detailed case study of splits between number subsystems in the Papuan language Nungon shows that the Animacy Hierarchy fails to account for the distribution of number subsystems there in three ways. First, the assumption that the subsystem with the most values must function at the top of the Animacy Hierarchy falters. Second, Nungon number subsystems are split both within a single paradigm and between multiple paradigms belonging to the same Animacy Hierarchy category. Third, splits between these subsystems also occur in a category, tense marking, that is apparently unrelated to the Animacy Hierarchy. Representation of number system splits as they relate or do not relate to the Animacy Hierarchy requires a three-dimensional schema rather than the linear Animacy Hierarchy. Finally, Nungon presents a previously unattested dependency between number and other grammatical systems.