The 24 Elders in Heaven are representatives of the Church - MEN.
As I have shown in the OP, they are not mankind. They existed before even this world was created.
Now, let's consider the 5th Seal.
Should we have to go over the first four "Seals" to understand they are given in Symbols, that we might understand earthly events?
The Fifth Seal is no different, for it refers to events on Earth. How do we know? The context. The texts reads that these "souls" were "under the Altar" - Rev. 6:9.
Question. According to the Scriptures, which Altar is this, the one in the Courtyard, or the Holy Place?
It is the one in the Courtyard. How do we know? Context. For the blood of the first group of Martyrs mentioned in it, was poured out at the base of that altar, just as it is given us:
And he shall put [some] of the blood upon the horns of the altar which [is] before the LORD, that [is] in the tabernacle of the congregation, and shall pour out all the blood at the bottom of the altar of the burnt offering, which [is at] the door of the tabernacle of the congregation. Leviticus 4:18
"And the priest shall ... shall pour out all the blood thereof at the bottom of the altar." Leviticus 4:30
And the priest shall take of the blood of the sin offering with his finger, and put [it] upon the horns of the altar of burnt offering, and shall pour out all the blood thereof at the bottom of the altar: Leviticus 4:34
And he shall sprinkle of the blood of the sin offering upon the side of the altar; and the rest of the blood shall be wrung out at the bottom of the altar: it [is] a sin offering. Leviticus 5:9
And he slew [it]; and Moses took the blood, and put [it] upon the horns of the altar round about with his finger, and purified the altar, and poured the blood at the bottom of the altar, and sanctified it, to make reconciliation upon it. Leviticus 8:15
And the sons of Aaron brought the blood unto him: and he dipped his finger in the blood, and put [it] upon the horns of the altar, and poured out the blood at the bottom of the altar: Leviticus 9:9
That Altar of Burnt Offering, in which the Blood was poured out at the base, upon the earth, was in the Courtyard, which represents the Earth, where Christ Jesus died. See Exo. 40:29, etc.
Therefore, the symbolism is pointing to the reality of Earthly events, not Heaven ones.
The Souls under The Altar cannot be understood, unless the structure, timing, language, types and symbols of the Scriptures be understood. The Altar deals with the portion of the Sanctuary and the service of the Great High Priest, Jesus Christ. The timing of the events listed in the 5th seal, are two fold, namely there are two groups mentioned. One group that has already died/martyred in the past, during the 1,260, and one group yet future to be so, coming soon. The second group is picked up in Revelation 20:4, as those "beheaded", and this prophecy event has yet to occur. The language itself also needs to be carefully considered, for there are similar passages in scripture.
The 5th Church, 5th Seal and 5th Trumpets are unique in their scope, as they are backward and forward looking from their point. They are connectors from the transition of the 4th and 6th of those things.
And when he had opened the fifth seal, I saw under the altar the souls of them that were slain for the word of God, and for the testimony which they held: Revelation 6:9
And I saw thrones, and they sat upon them, and judgment was given unto them: and [I saw] the souls of them that were beheaded for the witness of Jesus, and for the word of God, and which had not worshipped the beast, neither his image, neither had received [his] mark upon their foreheads, or in their hands; and they lived and reigned with Christ a thousand years. Revelation 20:4
See also Revelation 6:10-11 for context between the two verses.
In the first text we see that there were those "slain for":
[A1] "the word of God"
[B1] "the testimony [G3141] which they held"
In the second text we see that there will be those "beheaded for":
[B2] "the witness ["testimony" G3141] of Jesus"
[A2] "the word of God"
In Revelation 6:
And when he had opened the fifth seal, I saw under the altar the souls of them that were slain for the word of God, and for the testimony which they held: Revelation 6:9
And they cried with a loud voice, saying, How long, O Lord, holy and true, dost thou not judge and avenge our blood on them that dwell on the earth? Revelation 6:10
And white robes were given unto every one of them; and it was said unto them, that they should rest yet for a little season, until their fellowservants also and their brethren, that should be killed as they were, should be fulfilled. Revelation 6:11
We are dealing with symbols, as we have been in the previous 4 seals Revelation 6:1-8. We are not looking at literal people stuck under a giant sanctuary fixture somewhere.
We see these "crying" out, we must understand this, that their martyred selves, by their shed blood upon the earth cries out for Justice, even as Abel's was spilled to the ground:
And he said, What hast thou done? the voice of thy brother's blood crieth unto me from the ground. Genesis 4:10
And to Jesus the mediator of the new covenant, and to the blood of sprinkling, that speaketh better things than that of Abel. Hebrews 12:24
That upon you may come all the righteous blood shed upon the earth, from the blood of righteous Abel unto the blood of Zacharias son of Barachias, whom ye slew between the temple and the altar. Matthew 23:35
From the blood of Abel unto the blood of Zacharias, which perished between the altar and the temple: verily I say unto you, It shall be required of this generation. Luke 11:51
Other things also "cry out" in scripture, but are not actually alive:
For the stone shall cry out of the wall, and the beam out of the timber shall answer it. Habakkuk 2:11
And he answered and said unto them, I tell you that, if these should hold their peace, the stones would immediately cry out. Luke 19:40
Other things also "cry out":
My soul longeth, yea, even fainteth for the courts of the LORD: my heart and my flesh crieth out for the living God. Psalms 84:2
Now notice that these are dead, and that they, by their shed blood, in which was the
Life - John 15:13, see also Genesis 9:4; Leviticus 17:11,14; Deuteronomy 12:23;, etc, are symbolically crying out for justice, even as Abels Blood shed from the foundation of the world, and they should "rest" [sleep of death in the grave] a little season longer "until" something was to happen... and that something is the slaying of the rest of the martyrs in the end, and will be vindicated in the Resurrection.
Rest/Sleep:
[sleep, asleep, sleepeth] Deuteronomy 31:16; 2 Samuel 7:12; Job 3:13, 7:21, 14:12; 1 Kings 1:21, 2:10, 11:21,43, 14:20,31, 15:8,24, 16:6,28, 22:40,50; 2 Kings 8:24, 10:35, 13:9,13, 14:16,22,29, 15:7,22,38, 16:20, 20:21, 21:18, 24:6; 2 Chronicles 9:31, 12:16, 14:1, 16:13, 21:1, 26:2,23, 27:9, 28:27, 32:33, 33:20; Job 14:12; Psalms 13:3; Matthew 27:52; John 11:11-13; Acts 7:60, 13:36; 1 Corinthians 15:6,18,20,51; 1 Thessalonians 4:13-15; 2 Peter 3:4; [awake] Job 14:12; Psalms 17:15; Isaiah 26:19; Daniel 12:2; John 11:11-13; [grave/bed] Job 17:13; Psalms 139:8; Luke 17:34; [fathers and prophets are dead] John 6:49,58, 8:52,53; Acts 2:29,34, 13:36; Hebrews 11:4,13,16,40
Do they have crowns yet according to the Symbolism and Prophecy? No.
Notice also the question,
"How long..." must they wait so? and a simple search will yield many answers in the OT/NT about this:
If I wait, the grave is mine house: I have made my bed in the darkness. Job 17:13
If a man die, shall he live again? all the days of my appointed time will I wait, till my change come. Job 14:14
When will God avenge them? Not until the other group of Martyrs comes, and them God will avenge both groups together, in the 7 last plagues -
"...rest yet for a little season, until their fellowservants also and their brethren, that should be killed as they were, should be fulfilled." Revelation 6:11
For they have shed the blood of saints and prophets, and thou hast given them blood to drink; for they are worthy. Revelation 16:6
After those things, comes Jesus, and the Resurrection to awaken the saints from the dust of the earth where they were asleep and waiting, knowing nothing. See 1 Thessalonians 4:13-18.