[206] Two Groups of 144,000 standing on mount Zion

1 And I saw, and, look! the Lamb standing upon the Mount Zion, and with him 144,000 having his name and the name of his Father written on their foreheads.
2 And I heard a sound out of heaven as the sound of many waters and as the sound of loud thunder; and the sound that I heard was as of harpers harping in the harps of them
3 And they are singing as if a new song before the throne and before the 4 living creatures and the elders; and no one was able to master that song but the 144,000, the [ones] having been bought from the earth.

4 These are [the ones] who did not defile themselves with women; because, they are virgins.
These are the ones that keep following the Lamb no matter where he goes.
These were bought from mankind as firstfruits to God and to the Lamb.

5 And in the mouth of them not was found lie. They are unblemished (Revelation 14).

The JWs have the event symbolic meaning of this to some extent. They have correctly recognised that there are only 144,000 1NC saints who make it to heaven. The earth could mean the planet or it could mean God's earthly organisation, i.e. the true religions, in this case FDS1 and FDS3 for the sanctification of the 1NC saints. Since the word 'earth' appears only once then it must take the same meaning in the word symbolism as well. Likewise the word 'heaven' appears only once, so it takes the same meaning in all accounts, namely the heaven where God lives.

The phrase 'the 144,000, the [ones] having been bought from the earth' is not a double designation, since each the second designation is meaningless in the absence of the first. 

So we have just one word symbolic meaning to add to the event symbolic meaning.

Event Symbolism

Lamb Greater Jacob (Jesus), the mediator of the 1NC
Mount Zion Kingship
144,000 All the non reserve 1NC saints who are sealed
Having his name on their foreheads Baptised into Jesus' name
Having his father's name on their foreheads Baptised into the name of the holy spirit, which name is God's name because the holy spirit is God's wife.
Heard a voice out of heaven, no one could master except the 144,000 The 144,000 are in heaven with the Lamb (Jesus).
No one could master the song but them This is their particular praise to Jehovah and to Jesus, their unique service etc.
The [ones] having been bought from the earth Called from the world and the church
They are virgins Spiritual virgins, never having brought a believer to baptism in a false church
They keep following the lamb no matter where he goes He goes from FDS1 to FDS2 in the first presence and from FDS3 to FDS4 in the second presence.

The First Word Symbolism

Lamb Greater Joseph (Gordon), the mediator of the 2NC
Mount Zion Kingship
144,000 All the non reserve 2NC saints who are sealed
Having his name on their foreheads Baptised into Gordon's name
Having his father's name on their foreheads Baptised into Michael's name, the everlasting father, through the ARC, the sealing covenant for the JAC.
Heard a voice out of heaven, no one could master except the 144,000 The 144,000 are in the heaven of Zoar with the Lamb (Gordon). 
No one could master the song but them This is their particular praise to Jehovah and to Jesus, their grasp of the code etc.
The ones having been bought from the earth The 2NC king/priests are bought from the fallen FDS3 and the world
They are virgins Spiritual virgins, never having brought a believer to baptism in a false church
They keep following the lamb no matter where he goes from FDS3 to FDS4
Firstfruits to God The first of the earth bound saints to enter into the kingdom

King David arranged his Kingdom as follows:

1 As for the sons of Israel by their number, the heads of the paternal houses and the chiefs of the thousands and of the hundreds and their officers that were ministering to the king in every matter of the divisions of those that came in and that went out month by month for all the months of the year, each division was 24,000.
2 Over the first division of the first month there was Jashobeam the son of Zabdiel, and in his division there were 24,000 (1 Chronicles 27:1,2)

12 divisions of 24,000 men making a total of 288,000. This then is the archetype for the total number of administrators in the Kingdom of God run by the root of David.