For the Definitive Edition , use the GOG Galaxy client to manage installation settings.
Q: Can I install the language pack on multiple platforms? A: The language pack may be platform-specific; check the system requirements before installation.
First and foremost, it's important to know that English is a fully supported, first-class language for Dawn of War II . The game was developed by Relic Entertainment in Canada, with English as its primary language. As a result, the English language files are not a "mod" or a "patch" but an integral part of the official game distribution on major platforms.