Actually, there is a rather robust generalization called Mahajan's Generalization, which states that ergativity is found in "verb peripheral" languages (VSO and SOV) but not in verb-medial languages (SVO).
So despite the fact that ergativity is a type of argument-alignment, it does appear to be directly related to word order (or, perhaps more accurately, whatever the structural underpinnings of word order are).
Mahajan, Anoop. 1994. The Ergativity Parameter: Have-be Alternation, Word Order and Split Ergativity. NELS 24.
Mahajan, Anoop. 1997. Universal Grammar and the Typology of Ergative Languages. In Alexiadou and Hall (eds.), Studies on Universal Grammar and Typological Variation.