As you say you don't have access to typoscript templates etc, I guess you are not an integrator/developer in this project, but an editor.
Your only way to achieve an automatic "fallback" behaviour is asking the person who takes care of the site's configuration to set that up for you.
But if that's not possible, you can still use the "insert records" content element (german: "Datensatz einfügen") to avoid duplicate entries.
This content type is not in the wizard when you create a new content element. But you can create a text element and then change the type to "insert records". Now you can select another record which is then mirrored here:
You'll have a similar amount of work when setting it up, but you won't have redundant text, which is way better.
If this content type isn't available either, I would insist on the administrator enabling it for editors - it's very useful to maintain a site's content healthy.