The term "Teutonic" is from a Latin word of complex etymology used to describe the Germanic people. During the Romanticism of the nineteenth century, it was applied to Scandinavia as well as Germany.

The Teutonic Knights refers to a medieval quasi-religious order of knights largely from the Germanies. The term "Teutonic" is applied because of their Germanic origin.

The use of the term "Teutonic" to describe pre-conversion mythologies of parts of Northern Europe should be taken only to mean "Germanic. If we said something about European mythologies, we would assume that we were talking about the pre-conversion stories and beliefs of Europe. Pointing out that medieval Europeans were largely Christian does not negate the fact that there were pre-conversion European mythologies.

I hope that helps.