Sīc scrīpsit Forcellīni:
K Græcorum littera est, non Latinorum, qui ejus loco c habent ejusdem potestatis.
What is the significance of the genitive case with habeō?
I gather that the sentence above means "K is a letter of the Greeks, not the Latins, who in its place give c the same meaning," i.e. habeō in its sense of "regard in a certain way". But I thought that that sense of habeō took a double accusative. Does the genitive here function like as in English "they regard c as producing the same sound"?
Can you show me a couple attestations of habeō, classical or otherwise, that illustrate its usage with the genitive in this way? Or if this meaning of the genitive also works with other verbs, an illustration or two of those?