Where do you get Armageddon in Revelation 20 the battle at Armageddon in Revelation 16 was the destruction of Babylon the great by the beast
Revelation 19:16-21
"And he hath on his vesture and on his thigh a name written, King Of Kings, And Lord Of Lords. And I saw an angel standing in the sun; and he cried with a loud voice, saying to all the fowls that fly in the midst of heaven, Come and gather yourselves together unto the supper of the great God; That ye may eat the flesh of kings, and the flesh of captains, and the flesh of mighty men, and the flesh of horses, and of them that sit on them, and the flesh of all men, both free and bond, both small and great. And I saw the beast, and the kings of the earth, and their armies, gathered together to make war against him that sat on the horse, and against his army. And the beast was taken, and with him the false prophet that wrought miracles before him, with which he deceived them that had received the mark of the beast, and them that worshipped his image. These both were cast alive into a lake of fire burning with brimstone. And the remnant were slain with the sword of him that sat upon the horse, which sword proceeded out of his mouth: and all the fowls were filled with their flesh."
This was the literal physical battle of Armageddon. Chapter 16 was the 3 spirits calling them to this physical battle. 17 and 18 was the symbolic application of the state of affairs the whole world was in at the end of those 42 months.
You cannot ignore the actual physical battle. You cannot separate the FP, the beast, and Satan from this physical event. The FP and the beast were tossed into the lake of fire. Satan was bound in the pit. This was the end of those 42 months to the hour.
The last hour was when the 10 kingdoms show up and join with Satan, the FP, and the beast. The battle was only an hour, because that was the only hour God allowed, the battle itself. Did the actual battle last for an hour? Hard to say. There was either time allowed for any to change their minds, or Jesus literally took an hour to kill every last one of them, instead of doing it instantly.