...Israel is in peace and safety mode when Ez 38 hits. So would they feel all secure after demolishing Damascus? I don't think they would be relaxed at all. Unless some how like they got away with it...and many months passed. And the hoards simmer over many months to surprise Israel....
One possibility is if the AC takes credit for what God does in Isaiah 17 and uses that to create the trust for Israel to sign the covenant, then after that is signed (and the Trib starts) the Ezek 38 happens.
I think several teachers hold to that, - I had a good list somewhere but would need to look up exactly who teaches that if anyone needs to know.
If I had to I'd say verse 4 brings a lot to light. "on" that day. That sounds like the day Damascus is destroyed Israel's glory radically fades. Same Day. Well that is the feeling. Maybe it starts on that day smaller and increases over time like. Not sure.
The difficulties here also seem to imply by the majority of the chapter that Israel shrinks in size. It is typically understood that Ez 38 reduces Israel to 1/3rd its population. Is 17 sounds something like that also. So if it is describing the same thing, is Is 17 the same day as Ez 38? Why would Saudi Arabia be asking if there is a spoil to take though? Like it would seem like a surprise. No one would be surprised if Israel though is attacked on the same day they attacked Damascus.
You're right about that diminished size of Israel after Isaiah 17. The geography suggests that Northern Israel is like that olive tree upper branches, where only a gleaning remain.
Ephraim (located in northern Israel- the area that civilians have been evacuated from currently) loses it's fortified city when Damascus disappears according to v 3 and the glory of Aram (Syria) is like the glory of Israel which sounds ok till v 4
In v 4 it continues to explain that the glory of Israel has faded. So now the comparison between the glory of Syria and Israel makes sense. Israel is in rough shape. Syria is worse. (there is a companion passage in Jeremiah 49:23-27 which gives even more detail IF it's the same event which I think it is. See v 25 there - remember that the "city of renown", that God delights in is Jerusalem, which is being compared to Damascus which fell completely and finally.)
v 5 brings up the valley of the Rephaim, which is the route of the Tel Aviv to Jerusalem train and delineates the northern area of Israel above Jerusalem.
v6 is talking about the gleanings. Any way you look at it, Israel takes a horrible hit. But not as bad as Damascus. Israel's upper branches (in the north just under the border with Syria) have a sparse few gleanings life while the tree itself remains.
I mentioned Jeremiah 49:23-27 which is a companion. Isaiah 17 speaks from Israel's point of view, while Jeremiah's passage speaks from Damascus's point of view. They are like a matched set, but one speaks about Damascus in detail, the other speaks of Damascus with more detail about Israel.
I tend to keep Zech 12 in the context of the final battle of Armageddon at the end of the Trib, I don't see it tied into Damascus or Ezek 38.
Looking at the differences:
Damascus in Isaiah 17 has the nations in tumult, roaring but God silences them (Jeremiah 49 hints that trouble for Damascus comes from the sea, and 2 northern cities are mentioned that survive today (Hama and Aleppo, both capitols of their provinces or governates)
Ezek 32:17-32 mentions a lot of the current day players including Elam and ties it in with terror PLUS Ezek mentions Syria in the context of ancient Asshur so it may or may not tie in. Jeremiah 49 mentions both Elam (south western part of modern Iran) as well as DAMASCUS which is why I see Ez 32:17-32 in context with Isaiah 17 AND Jeremiah 49.
Ezek 38 a specific group of nations attack Israel and God pours out His fire on them. While weapons burn for 7 years might hint at the 7 years of the Trib, God has some areas burning thruout the whole of the Millennial reign so it doesn't necessarily mean it's at the start of the Trib. However there are significant differences between the scenario of Ez 38 and the battle of Armageddon. Armageddon involves all the nations against Judah and Jerusalem.
Zech 12 has all the nations and has time specific verses placing it at the time of Armageddon/end of the Trib vs 10-14 which are the sequel to the way God delivers the nation and the city at that time.