All of these in 3 1/2 years? Also, have you considered flesh and blood cannot inherit the Kingdom? This means only saints in glorified bodies makeup the kingdom after Christ returns.
Just as side note, Dave, the term 3 1/2 years is not found in bible prophecy. The 1260 days would be exactly half of the 7 years would be the closest thing. But the other two terms - 42 months and the time, times, half times are used because those don't equate to exactly 1260 days. I know mathematically they do. But not in way they are used in bible prophecy.
Okay, to the large number in Revelation 7. It reflects the scale of death that will take place in the great tribulation. Jesus said if those days were not shortened (limited) no flesh would survive.
When Jesus returns, the souls of those saints in Revelation 7 will get their eternal resurrected bodies at the start of the 1000 years reign in Revelation 20:4. Revelation 7 is not the resurrected/raptured saints, but them who become Christians afterward, and die during the great tribulation.
It is the resurrected/raptured Christians -
takened earlier, before the great tribulation begins (when the abomination of desolation is placed in the temple) who will be returning with Jesus in their glorified eternal bodies.
Which the question then becomes - what kind of bodies do them in Revelation 7 have then? I don't know. The souls will apparently have some sort of body to be perceptible for John to have seen them. Not enough information to elaborate on though.
Apart from Christians before, after, and during the great tribulation - when the Kingdom of God is brought to earth, there apparently will be a number (not enough information to know how many) who are not Christians, who will survive, and will continue into the millennium. They will be part of the re-population, along with Christians who live through it.
There will still be the same nations - continue into the millennium, from what it says in Zechariah 14, regarding attending the feast of tabernacles, and in Daniel 7 about the three beasts allowed to live a little longer but their dominion taken away. The fourth beast though, that governing union will not be allowed to continue.
On the issue of flesh and blood cannot inherit the Kingdom of God is fundamental to a person must be born again of the Spirit.