"Eidem suae": a way to make the reflexive pronoun refer to someone other than the subject?

Question

(A tangent off this speculative answer to a question about a sentence containing the words eidem suae.)

Does the apparently redundant phrase eidem suae ("to his/her/its own same") provide a way to indicate that the antecedent of suae is not the subject of the verb, as is normal for the reflexive pronoun in the dative case, but something else having a (different) reflexive relation to whatever follows suae?

A possible example, from the Apostolic Letter "Quod De Beatissima" by Pope Pius XII (1957):

Venerabilis Frater Constantinus Christianus Luna, Episcopus Zacapensis, a Nobis enixe postulavit, ut eidem suae dioecesi, noviter conditae nulloque Patrono adhuc concreditae, eandem Virginem a Fatima caelestem Patronam benigne eligere dignaremus.

This is a little beyond my current skill with Latin, but here's my attempt at a translation:

The venerable Brother Constantine Christian Luna, Bishop of Zacapa, has strenuously asked us, for his own newly founded diocese, as yet entrusted with no Patron, that we deem worthy to kindly choose Our Lady of Fatima as Patroness.

The subject of the relevant clause is the author, that is, the Pope. It would be silly if Luna asked the Pope to choose a Patroness for his own—the Pope's own—diocese, but that's what suae dioecesi would literally mean. So, I'm wondering if eidem suae is a way to relocate the antecedent of suae to where it makes sense and thus avoid a very clumsy circumlocution. And is this a common idiom?

If the same thing commonly occurs in another grammatical case, that would answer the question, too.

Answer 1

To reiterate @Cerberus's answer, the reflexive usually refers to the subject of the main/independent clause. In this case, this is especially clear, since the Pope is using the "royal we" to refer to himself, and thus would use noster instead of suus to refer to himself.

I am writing this answer, though, to address the actual question in your title. The answer is yes, there are certainly examples of reflexive pronouns referring to someone other than the subject.

In Oxford Latin Syntax: Volume I, the Simple Clause, Pinkster says the following:

In complex sentences a constitutent of the subordinate clause may be coreferential with a constituent of its own clause (normally the subject) or with a constituent of the governing clause, not necessarily the subject. (pg. 1124)

(emphasis mine)

As an example of this, he quotes Cicero:

Vos ex M. Favonio audistis Clodium sibi dixisse, et audistis vivo Clodio, periturum Milonem triduo. (Cic. Mil. 44)

This sentence is perhaps easier to parse because "ex aliquo audio" can be transposed without difficulty to aliquis dicit. Still, I believe this is an enlightening example from an authoritative source of a reflexive not referring to a subject.

Answer 2

This eidem suae sounds unclassical to me. But Church Latin is full of Mediaevalisms.

The subject of the sentence is Venerabilis Frater Constantinus Christianus Luna, Episcopus Zacapensis, so I would take suae to refer to him. If it should refer to nobis, I would expect nostrae. I believe suus/se/sibi normally refers to the subject of the main clause, not the subject of the subordinate clause, but that exceptions are not uncommon. The subject of the subordinate clause would still have to be the third person, though.

As to eidem: I believe that can be used to mean "aforementioned" in later Latin (cf. English he who takes out a book from the library must return same within the space of two weeks).