The preparations for the invasion (Jdt 4:4-4:8)

“The Israelites sent word to every district of Samaria, especially to Kona, Beth-horon, Belmain, Jericho, Choba, Aesora, and the valley of Salem. They immediately seized all the high hilltops. They fortified the villages on them. They stored up food in preparation for war, since their fields had recently been harvested. The high priest Joakim, who was in Jerusalem at the time, wrote to the people of Bethulia and Betomesthaim, which faces Esdraelon opposite the plain near Dothan. He ordered them to seize the mountain passes, since by them Judea could be invaded. It would be easy to stop any who tried to enter, for the approach was narrow, only wide enough for two at a time to pass. So the Israelites did as they had been ordered by the high priest Joakim and the senate of the whole people of Israel, in session at Jerusalem.”

The Israelites were aware that Holofernes was coming. They warned the people of Samaria. However, Judah was always separate from Samaria and Holofernes was already there in northern Israel. There were a series of towns in Benjamin named, some of which are difficult to locate except for Beth-horon and Jericho. The valley of Salem may refer to the area around Jerusalem since that might have been ancient name, Jeru-Salem. They took all the high places and fortified them. They stored up food since the harvest had just taken place. The 2 towns of Bethulia and Betomesthaim are difficult to find. They must have been near Dothan, which as far as any identification is possible, was north of Shechem in Manasseh territory. Their high priest Joakim is also hard to identify, since the only priest with that name was after the exile in Nehemiah, chapter 12. This would put it 200 years after King Nebuchadnezzar. There also was no Senate in Jerusalem until the 2nd century BCE. Thus the story has a lot of problematic areas when it comes to specifics about places, peoples, and events in any sort of timeframe.