‘United and solid EU’ doesn’t have to involve forcing everyone to use a someone’s native language. Ideally we’d have a common language that’s neutral and used for international communication only. In fact, we already have a working solution; Esperanto has existed for well over 100 years at this point, and continues to be a healthy, living language. People just don’t seem to care that much. It always seems to be either practicality or national heritage, never both at the same time. Yet the common ground has been there all along.