I was under the impression that this was the second Ogres War in this episode. The first was when he deserted and broke his leg when Bae was an infant.
They flashed “first Ogres war” on the screen at the very beginning which was when Rumple broke his leg, before Bae was born. It apparently lasted a long time in spite of the fact that Rumple “killed them all” and in The Return says he ended the war.
The impression I got from “Desperate Souls” and “Manhattan” is that it’s the same war (that’s how long it’s been going on), with the second being the one in “Skin Deep,” and the third being the one in S2.