This paper describes our tools and method for an evaluation of the practical and logical implications of combining com-mon linked data vocabularies into a single local logical model for the purpose of reasoning or performing quality evalua-tions. These vocabularies need to be unified to form a combined model because they reference or reuse terms from other linked data vocabularies and thus the definitions of those terms must be imported. We found that strong interdependen-cies between vocabularies are common and that a significant number of logical and practical problems make this model unification inconsistent. In addition to identifying problems, this paper suggests a set of recommendations for linked data ontology design best practice. Finally we make some suggestions for improving OWL’s support for distributed authoring and ontology reuse.