Obadiah's synoptic-problem

Among the Biblical texts given credence by the recent magnetic discoveries in ruined Israeli[te] cities, is Obadiah. This "servitor of YHw" is among the Twelve Minor Prophets.

In Greek form, Obadiah was likely always in that collection (pdf). The Nahal Hever fragments witness a collection of Minor Prophets in Greek, although we're unsure if Rahlfs 943 was truly a "8HevXIIgr" since our book isn't in it. Also the overall "Septuagint" collection was translated by one person (or by a very tight committee). Questions remain about the author's familiarity with the Greek Jeremiah.

Obadiah owns thematic parallels with the full text of Psalm 137 (136 in Greek) inasmuch as both encapsulate an antiEdomite polemic. It owns text parallels with Jeremiah 49 (in MT edition; 'tis 29 in LXX) such that it's a Synoptic Problem. Most assume that Obadiah used Jeremiah.

Obadiah does have an agenda and has likely inverted a text, here Semitic treaty boilerplate. Psalm 137's parallels with Obadiah can be explained as sharing this subversion of the treaty topos, in the psalm's case Aramaic. Both would then react to a perceived betrayal of Judah from Edom. I find this plausible.

Whether we assume that Obadiah has likewise riffed on the future Jeremiah 49 is another matter. Some (mostly evangelical) argue for Joel's use of Obadiah which would put Obadiah's polemic 801 BC, long before Jeremiah. Wikipedia prefers Ehud Ben Zvi's 1996 argument that as Obadiah imposes his views upon the shared text... so does Jeremiah. Behind each is, then, a "Q".