Nah, it doesn't really violate the Shema. It only violates your MIS-interpretation of the Shema.
Why, exactly, can't Three separate and distinct divine beings/entities make up one God (or Godhead)?
Why, exactly, can't Eight conjoined and identical orangutans/chimpanzees make up one God (or Godhead)?
Anyone can make up any definition they want to redefine what One God means to cater to whatever whims suit them.
The Lectures on Faith define the Godhead as two personages.
GA's have asserted there is a Heavenly Mother with all the attributes of Deity.
Brigham Young taught that Adam is God.
Lorenzo Snow said God was once mortal man.
Again, I don't have to prove a negative. You have the burden to prove your redefinition correct.
There in only one God:
Then he said, "Tomorrow." So he said, "May it be according to your word, that you may know that there is no one like the LORD our God.
To you it was shown that you might know that the LORD, He is God; there is no other besides Him.
Know therefore today, and take it to your heart, that the LORD, He is God in heaven above and on the earth below; there is no other.
Hear, O Israel! The LORD is our God, the LORD is one!
—Deuteronomy 6:4, cf. Mark 12:29
See now that I, I am He, and there is no god besides Me ...
There is no one holy like the LORD, indeed, there is no one besides You, nor is there any rock like our God.
—1 Samuel 2:2
... O Lord GOD; for there is none like You, and there is no God besides You ...
—2 Samuel 7:22
O LORD, there is none like You, nor is there any God besides You...
—1 Chronicles 17:20
You alone are the LORD, You have made the heavens, the heaven of heavens with all their host...
... So that you may know and believe Me and understand that I am He, before Me there was no God formed, and there will be none after Me.
Thus says the LORD, the King of Israel and his Redeemer, the LORD of hosts: 'I am the first and I am the last, and there is no God besides Me.'
... Is there any God besides Me, Or is there any other Rock? I know of none.
I am the LORD, and there is no other; Besides Me there is no God ...
For thus says the LORD, who created the heavens (He is the God who formed the earth and made it, He established it and did not create it a waste place, but formed it to be inhabited), "I am the LORD, and there is none else."
... And there is no other God besides Me, A righteous God and a Savior; There is none except Me. "Turn to Me and be saved, all the ends of the earth; For I am God, and there is no other.
Remember the former things long past, For I am God, and there is no other; I am God, and there is no one like Me.
There is none like You, O LORD; You are great, and great is Your name in might.
And the scribe said unto him, Well, Master, thou hast said the truth: for there is one God; and there is none other but he.
—Mark 12:32 KJV
Seeing it is one God, which shall justify the circumcision by faith, and uncircumcision through faith.
—Romans 3:30 KJV
Therefore concerning the eating of things sacrificed to idols, we know that there is no such thing as an idol in the world, and that there is no God but one.
—I Corinthians 8:4
Now a mediator is not for one party only;
whereas God is only one.
You believe that God is one
You do well; the demons also believe, and shudder.
And Zeezrom said unto him:
Thou sayest there is a true and living God?
And Amulek said: Yea, there is a true and living God.
Now Zeezrom said: Is there more than one God?
And he answered, No.
...See that ye remember these things; for he said there is but one God...
And the people ... also testified that there was but one God ...
And the honor be to the Father, and to the Son, and to the Holy Ghost, which is one God. Amen.
—Testimony of Three Witnesses
... And now, behold, this is the doctrine of Christ, and the only and true doctrine of the Father, and of the Son, and of the Holy Ghost, which is one God, without end. Amen.
—2 Nephi 31:21
... unto the Father, and unto the Son, and unto the Holy Ghost, which are one God, in a state of happiness which hath no end.
... Christ the Son, and God the Father, and the Holy Spirit, which is one Eternal God ...
For if there be no Christ there be no God; and if there be no God we are not, for there could have been no creation. But there is a God, and he is Christ, and he cometh in the fullness of his own time.
—2 Nephi 11:7
For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost; and these three are one.
—1 John 5:7 JST
The Father being a personage of spirit... The Son, who was in the bosom of the Father, a personage of tabernacle, made or fashioned like unto man... is called the Son because of the flesh... possessing the same mind with the Father; which Mind is the Holy Spirit... and these three are one... and these three constitute the Godhead and are one: the Father and the Son possessing the same mind... the Spirit of the Father.
—Doctrine & Covenants: Lectures on Faith, V (removed 1921)
For unto us a child is born, unto us a son is given: and the government shall be upon his shoulder: and his name shall be called Wonderful, Counsellor, The mighty God, The everlasting Father, The Prince of Peace.
—Isaiah 9:6, cf. The Book of Mormon, 2 Nephi 19:6
Now Zeezrom saith again unto him: Is the Son of God the very Eternal Father? And Amulek said unto him:
Yea, he is the very Eternal Father
—The Book of Mormon, Alma 11:38-39
And they are one God, yea, the very Eternal Father of heaven and of earth.
—The Book of Mormon, Mosiah 15:4
...Behold, I am Jesus Christ. I am the Father and the Son...
—The Book of Mormon, Ether 3:15
... no man knoweth that the Son is the Father, and the Father is the Son, but him to whom the Son will reveal it ...
—Luke 10:23 JST, cf. Luke 10:22
None of these verses state that God or "the Godhead" is comprised of "Three Gods". In fact, no verses in the Bible (or Book of Mormon, or JST) support your definition.
And when everyone says that the earth is flat, then what?
When the minority is right, they win over the majority because they have facts behind them.
Ok, so now your God has multiple personality issues. I get it.
You obviously have no coherent response to this point.
So then you CAN'T claim that we are wrong, then can you.
I don't need to know the DNA of an apple to recognize that an orange is not an apple.
Atheism: the belief that there was nothing and nothing happened to nothing and then nothing magically exploded for no reason, creating everything, and then a bunch of everything magically rearranged itself for no reason whatsoever into self-replicating bits which then turned into dinosaurs.