Hi Dimitri,
You're most definitely right in your assumption that this is incorrect. Those are not even properly written hreflang tags, and are therefore useless.
The purpose of hreflang is to help search engines determine which language version of an otherwise duplicate webpage should be served to a user in a particular geographical area. Therefore, each individual hreflang tag includes both a country and a language. For instance, if you want users finding you through search in the US to be served the English language version of a webpage, the hreflang tag would be as follows:
However, if you wanted your users in Canada to be served the French version of a webpage (if it's targeted at a Quebecoi audience for instance), the hreflang tag would be as follows:
I don't think your current hreflang tags are damaging you as they're incorrectly formatted and probably therefore disregarded, but you should at the very least remove them until they've constructed an accurate hreflang set. How many languages is your site in?
Hope this helps!