TransUnit holds a single source and single target - each of these can either be a single string or a small set of plural forms representing the same unit of text (depending on the number of plural forms specified for the locale). If the translations in the workspace locale are being fetched at the same time as the translations in the other selected locale, it would make sense to bundle them as a TransUnit, but I have a feeling we can do better than that with a bit of revision of our data model for transfer.