I checked Revelation 19 a bit:
The Rider on a White Horse
11 Then I saw jheaven opened, and behold, ka white horse! The one sitting on it is called lFaithful and True, and min righteousness he judges and makes war. 12 nHis eyes are like a flame of fire, and on his head are omany diadems, and he has pa name written that no one knows but himself. 13 He is clothed in qa robe dipped in4 blood, and the name by which he is called is rThe Word of God. 14 And the armies of heaven, sarrayed in fine linen, white and pure, twere following him on white horses. 15 uFrom his mouth comes a sharp sword vwith which to strike down the nations, and whe will rule them with a rod of iron. xHe will tread the winepress of the fury of the wrath of God the Almighty. 16 On his robe and on his thigh yhe has a name written, zKing of kings and Lord of lords.
17 Then I saw an angel standing in the sun, and with a loud voice he called to aall the birds that fly directly overhead, b“Come, gather for cthe great supper of God, 18 dto eat the flesh of kings, the flesh of captains, the flesh of mighty men, the flesh of horses and their riders, and the flesh of all men, both free and slave,5 both small and great.” 19 And I saw ethe beast and the kings of the earth with their armies fgathered to make war against him who was sitting on the horse and against his army. 20 And the beast was captured, and with it gthe false prophet hwho in its presence6 had done the signs by which he deceived those who had received the mark of the beast and those who iworshiped its image. These two were jthrown alive into the lake of kfire that burns with sulfur. 21 And the rest were slain by the sword lthat came from the mouth of him who was sitting on the horse, and mall the birds were gorged with their flesh.
OK in short Christ returns, the beast and its armies march up against him, but the beast and the false prophet are captured, their following is slain. So the enemies are exterminated like vermin and the birds will eat the flesh. That will strike down (sudue) the nations, but he also will rule them with a rod of iron.
I don't see that those nations will be exterminated completely, just those members of the nations that collaborated with the beast (e.g. by accepting the mark of the beast). It makes perfect sense that some survivalists will be able to populate the 1000 year kingdom then.
So I think this is some mental acrobatics and a false dilemma to force a pre-tribulation rapture point of view, when Jesus clearly says in Mark 13:
24 But in those days, after that tribulation, the sun shall be darkened, and the moon shall not give her light, 25 and the stars of heaven shall fall, and the powers that are in heaven shall be shaken. 26 And then shall they see the Son of man coming in the clouds with great power and glory. 27 And then shall he send his angels, and shall gather together his elect from the four winds, from the uttermost part of the earth to the uttermost part of heaven.
So they first will see Christ returning, then the angels will gather the Elect.