No language will prevent a team of developers from building an un-maintainable mess no matter how good it is (and I have seen a few). Proper design skills and knowledge of ‘good’ software architecture will make or break a project every time. Stop getting hung up on languages.
Unless you’re being asked to develop in C (then I applaud you), then agree on a language that will still exist in 6 months time and then on with the difficult part...writing decent code.