English IS a Germanic language. That fact has been known for centuries. See any history of the English language. After thousands of years living in proximity to each other of course words from other languages enter a peoples language; German borrowed its word for window from its French neighbors. Words coming in are “loan Words.”
60 to 70 percent of English is latin-based, most of that arriving from the Normans, who spoke Norman French, but some of it coming from the Roman era. The old Germanic form of English (pre-conquest) is no longer comprehensible to an English speaker. English survived the conquest through many of the important, basic words and the grammar, but the language is much different, and to my ear, better. It has multiple words for just about anything, any concept. It allows a writer or speaker to come up with all kinds of beautiful ways to express an idea or describe a scene.