I notice that we have a Category:European goddesses. It would appear that most European goddesses are individual personas, just like everywhere else. I think what some writers appear to have done is gather evidence that a particular triplet of goddesses associated with fate seems to be attested across Europe (going way back to whenever).
I think a little confusion arises because this reality was expanded upon and popularised by Graves (19th century) and others, leading ultimately to pride of place for the Triple Goddess in neopaganism (20th century), and later popularised again by certain elements within the feminist movement (late 20th century).
Ultimately, we don't have to restrict material to only one article. I doubt that the US civil war is left out altogether from the article on the US, just because it has its own article. ;)
I think Fuzzypeg's main concern is ensuring that Wikipedia documents the scholarship regarding pre-19th century triplicate goddesses in Europe. We possibly need a hatnote or "main article" link to bloodofox' List of goddesses appearing in trios in mythology (or a proper article, with a more sexy title, 8 words is a lot for a title, no offence intended).