Prophet Brigham Young (1801 - 1877):
While brother Joseph was referring to the provinces of God, I was led to reflect that there is no act, no principle, no power belonging to the Deity that is purely philosophical. The birth of the Saviour was as natural as are the births of our children; it was the result of natural action. He partook of flesh and blood was begotten of his Father, as we were of our fathers.
(Prophet Brigham Young, Journal of Discourses, v. 8, p. 115)
... I believe the Father came down from heaven, as the apostles said he did, and begat the Saviour of the world; for he is the ONLY-begotten of the Father, which could not be if the Father did not actually beget him in person.... I believe the Father came down in His tabernacle and begat Jesus Christ.
(Prophet Brigham Young, Journal of Discourses, v. 1, p. 238)
Apostle Heber C. Kimball (1802 - 1868):
... In relation to the way in which I look upon the works of God and his creatures, I will say that I was naturally begotten; so was my father, and also my Saviour Jesus Christ. According to the Scriptures, he is the first begotten of his father in the flesh, and there was noting unnatural about it.
(Apostle Heber C. Kimball, Journal of Discourses, v. 8, p. 211)
Apostle Orson Pratt (1811 - 1881):
God, the Father of our spirits, became the Father of our Lord Jesus Christ according to the flesh.... The fleshy body of Jesus required a Mother as well as a Father. Therefore, the Father and Mother of Jesus, according to the flesh, must have been associated together in the capacity of Husband and Wife; hence the Virgin Mary must have, for the time being, the lawful wife of God the Father.... He had a lawful right to overshadow the Virgin Mary in the capacity of a husband, and beget a Son, although she was espoused to another; for the law which He gave to govern men and women, was not intended to govern Himself, or to prescribe rules for his own conduct.
(Apostle Orson Pratt, The Seer, p. 158)
Prophet Joseph F. Smith (1838 - 1918):
Now, we are told in scriptures that Jesus Christ is the only begotten Son of God in the flesh. Well, now for the benefit of the older ones, how are children begotten? I answer just as Jesus Christ was begotten of his father...Now my little friends, I will repeat again words as simple as I can, and you ask your parents about it, that God, the eternal Father, is literally the father of Jesus Christ.
(Prophet Joseph F. Smith, Family Home Evening Manual, pp. 125, 126, 1972)
Prophet Joseph Fielding Smith (1876 - 1972):
Christ Not Begotten of Holy Ghost... Christ was begotten of God. He was not born without the aid of Man, and that Man was God!
(Prophet Joseph Fielding Smith, Doctrines of Salvation, v. 1, p. 18, 1954)
Apostle Bruce R. McConkie (1915 - 1985):
Christ was Begotten by an immortal Father in the same way that mortal men are begotten by mortal fathers.
(Apostle Bruce R. McConkie, Mormon Doctrine, p. 547, 1966)
And Christ was born into the world as the literal Son of this Holy Being; he was born in the same personal, real, and literal sense that any mortal son is born to a mortal father. There is nothing figurative about his paternity; he was begotten, conceived and born in the normal and natural course of events, for he is the Son of God, and that designation means what it says.
(Apostle Bruce R. McConkie, Mormon Doctrine, p. 792, 1966)
As far as this life is concerned, [Jesus] was born of Mary and of Elohim; he came here as an offspring of that Holy Man who is literally our Father in heaven. He was born in mortality in the literal and full sense as the Son of God. He is the Son of his father in the same sense that all morals are the sons and daughters of their fathers.
(Apostle Bruce R. McConkie, Mortal Messiah, v. 1, p. 330)
Prophet Ezra Taft Benson (1899 - 1994):
The Church of Jesus Christ of Latter-day Saints proclaims that Jesus Christ is the Son of God in the most literal sense. The body in which He performed His mission in the flesh was sired by that some Holy Being we worship as God, our Eternal Father. Jesus was not the son of Joseph, nor was He begotten by the Holy Ghost.
(Prophet Ezra Taft Benson, The Teachings of Ezra Taft Benson, p. 7)
Having no knowledge of the references you cite, I would have to investigate them before giving them any weight whatsoever.
Prophets speak, and they also speak "as prophets". Perhaps that's a difference here.
The way I heard it was that God caused Mary to become with child, and that Mary was a virgin. Seems to me that God who created the universe could accomplish that without having sex with Mary, else how could she still be a virgin - as is clearly stated ?