In response to the increasing challenge of integrating students with migration backgrounds into school systems internationally, various models to support the learning of the language of education have emerged. In Austria, a model of 'German Language Support Classes' (GLSC), introduced in 2018, requires that students be pulled out of regular class teaching and taught German in a segregative context. Critics argue that this approach contradicts evidence-based language learning and principles of inclusive education, and that it diminishes school autonomy. With this in mind, we present a qualitative interview study comprising 25 primary teachers of German language in Vienna, Austria, which aims to capture their beliefs about what constitutes 'ideal practice' in language education and to explore the extent to which these beliefs are evidence-based. A typological analysis reveals that there is a 'segregative type', an 'integrative type', and an 'in-between type'. Although teachers' perceptions of language education differ, their understandings are similarly shaped by a monolingual habitus. Our findings provide evidence for the inappropriateness of this language education model and reveal aspects of teacher education needed to lead to better outcomes in language education.