No, I think you raise a cogent point. It's worth reflecting on, though there's also that old saw, "birds of a feather flock together." It may be that opposites attract, in a sense, but not in the same way that similarities congregate--the former perhaps creating a sort of antagonistic harmony (?).

Some references on similarities and its use in rites, from Iamblichus (online translation): "The explanation which is now made is far superior, which does not assume that divine operations are accomplished by means of contrary or different natures, as things of nature are wont to be effected; but, instead, that every work is rightly accomplished through sameness, oneness and conformity of nature."

And again: "Indeed, there is a certain creative activity of various kinds extending from the whole universe into the parts either from sympathy through similarity of powers, or from the adaptation of the active to the passive principle."

Emphases mine.