"可能性がある" at the beginning of a sentence?

Question

I'm reading a short extract from a story, and I'm having troubles understanding the syntax of the following:

可能性があるとすればギンの『生贄』を免れた山田とその父親だけだが、敵である男達が使えた所でなんだと言うのだと考え、チヒロは肩を竦めた。

I'm used to seeing 可能性がある at the end of a clause but so far have never seen in at the beginning (bear in mind I only have about one year experience as a student in Japanese) I'm not sure how this would translate to English.

My best attempt at a translation is:

Although if there is a possibility, only Yamada and his father escaped gin's "sacrifice", Chihiro shrugged her shoulders thinking that the men that are the enemies were able to use it. (?)

This doesn't sound right to me and I'm confused by what it's trying to say.

Is the 可能性があるsupposed to refer to something previously mentioned? And that's why it's at the beginning of the clause? Or is it encompassing whatever comes later in the clause? I hope someone can help me understand this thank you!

Answer 1

Your translation attempt is close.

（もし）可能性があるとすれば、（それは）ギンの『生贄』を免れた山田とその父親だけだ
If there is (such) a possibility, that would be Yamada and his father, who have escaped from being Gin's "sacrifice".

が、「敵である男達が使えた所でなんだと言うのだ」と考え、チヒロは肩を竦めた。
But Chihiro shrugged her shoulders, thinking "So what if men who are enemies are usable?"

In this context, yes, 可能性 basically refers to the "possibility" of something mentioned in the previous statements. But there is a hint in this sentence, too; the 可能性 here refers to 誰かが使える可能性 (possibility that someone is "usable"). Note the subject of 使う is Chihiro, not the men (see: The difference between が and を with the potential form of a verb.)

I don't know what 使う exactly means in this context, but if I understand correctly, being a ギンの生贄 makes a person "unusable" for Chihiro in this context. She was wondering who were "usable" (使える), but the only possibility that came to her mind was Yamada and his father.

See this article for the usage of ～た所で here. なんだというのだ is a set phrase meaning "so what?", "does that matter?", "who gives a damn?", etc. だからどうした, それがどうした, だからなんだ are similar.

(Note: There is an ambiguity about what ギンの生贄を免れた modifies. It may modify only 山田, but it may modify both 山田 and その父親.)