The problem with apocalyptic prophecies is that you can make them fit just about anything you please.
The simple JW resolution to your argument (and I'm not saying this is or isn't or indicating agreement in any direction) would be "Well even if it says Jehovah, it just means he's behind it. Let me find another verse from Revelation to show you that you have to read the bible as a whole inerrant and literal book, apart from the bits which we've decided aren't."
My understanding of JW belief, certainly so when I was in, was that it was Jesus doing the Armageddon thing. He's the one leading the cavalry charge at the end of My Book of Bible Stories. ;)