Say I want to build links to a german site. Are english backlinks and .edu/.gov backlinks as much worth as german backlinks? In this example I want to rank in german google.
It's a backlink never the less, but the traffic it gives would be worthless, your better off promoting on as many german websites as you can first, then if you ever run out, go onto english sites.
Almost any backlink helps your site. But a backlink from a German site will give you more link juice and a german site in your niche will give you even more link juice.