Joseph Smith did not DENY the real Jesus. He postulated a different Jesus than found in the Bible. However Ellen G. White was thoroughly confused about who Jesus is, and even contradicted herself:
JESUS DID NOT CEASE TO BE GOD
From Letter 32, 1899, quoted in the SDA Bible Commentary, Volume 5, pg. 1129 we have Ellen White stating: "But although Christ's glory was for a time veiled and eclipsed by His assuming humanity, yet He did not cease to be God when He became man...
JESUS WAS NOT THE LORD GOD ALMIGHTY
...The man Christ Jesus was not the Lord God Almighty, yet Christ and the Father are one."
From her writings in Desire of the Ages, she says:
JESUS WAS MICHAEL THE ARCHANGEL
"The words of the angel, 'I am Gabriel, that stand in the presence of God', show that he holds a position of high honor in the heavenly courts. When he came with a message to Daniel, he said, 'There is none that holdeth with me in these things, but Michael (Christ) your prince'." (Dan. 10:21) (THE DESIRE OF AGES, p99.)
And from her writings in Spiritual Gifts. she says:
"Michael, or Christ, with the angels that buried Moses, came down from Heaven, after he had remained in the grave a short time, and resurrected him, and took him to Heaven."
and,
"As Christ and his angels drew nigh, Satan resisted their approach, but was compelled, by the glory and power of Christ and his angels to fall back. Satan claimed the body of Moses, because of his one transgression; but Christ meekly referred him to his Father, saying, "The Lord rebuke thee." " (SPIRITUAL GIFTS, Vol 4, Pg. 58)
Essentially both Joseph Smith and Ellen G. White were FALSE prophets/prophetesses. They created a lot of spiritual confusion, and obviously their gospels are false.