I mean I suppose I can see it as the rape of the Sabines,

Of which it certainly has elements. I am still re-reading, but I recall that they initially raid a farm for does; in the case of Efrafa, it just happens to be their luck that Hyzenthlay and others already want to leave.

but if they had all left Troy and had those adventures Hekabe and Andromache would have been there.

Yes. If Kassandra had been listened to; and been her brother.