It would be helpful if you checked your facts before making claims that are incorrect.
Spurgeon on Psalm 8:5-8. 'These verses may set forth man's portion among the creatures before he fell; but as they are, by the apostle Paul* appropriated to man as represented by the Lord Jesus, it is best to give most weight to that meaning. In order of dignity, man stood next to the angels, and a little lower than they; in the Lord Jesus this was accomplished for He was made a little lower than the angels by the suffering of death. Man in Eden had the full command of all creatures, and they came before him to receive their names as an act of homage to him as the viceregent of God to them. Jesus, in His glory, is now Lord, not only of all living, but of all created things, and with the exception of Him who put all things under Him, Jesus is Lord of all, and His elect, in Him, are raised to a dominion wider than that of the first Adam, as shall clearly be seen at His second coming.' [from Spurgeon's 'Treasury of David']
*Spurgeon believed that Paul wrote the Letter to the Hebrews.
And you are disingenuous in your quotation of Edward Young's poem, because you know perfectly well that he also quoted another poem on the facing page, part of which reads,
'Lord, what is man that thou
So mindful art of him? Or what's the son
Of man, that thou the highest heaven didst bow,
And to his side did runne?
Baser than clay is he,
For sin hath made him like the beasts that perish,
Though next the angels he was in degree;
Yet this beast thou dost cherish.
He is not worthy of the least
Of all thy mercies, he's a beast.
Worse than a beast is man,
Who after thine own image made at first,
Became the devil's sonne by sin. And can
A thing be more accurst?
Yet thou they greatest mercy hast
On this accursed creature cast.
Thou didst thyself abase,
And put off all thy robes of majesty,
taking his nature to give him that grace,
To save his life didst dye.
He is not worthy of the least
Of all thy mercies; one's a feast.
Lo! Man is made now even
With the blest angels, yea, superior farre,
Since Christ sat down at God's right hand in heaven.
And God and man one are,
Thus all thy mercies man inherits,
Though not the least of them he merits.' [Thomas Washbourne]
Yet this is not really the point. The point is that the translator does not have the right to prevent his readers from finding Christ in the text by turning singulars into plurals. If Carson and MacArthur are so wilfully blind that they cannot find Christ in Psalm 8 (something I find very hard to believe), that is their choice and their loss. But they don't have the right to deny to the reader the opportunity to obey the exhortation of his Saviour and find Him in all the Scriptures.