Not from how I see it. You are saying that belief in Christ as the Savior and His death wasn't good enough for salvation. You've added on the ADDITIONAL "requirement" that one has to BELIEVE IN Joseph Smith. Christ never said that belief in Him wasn't good enough. LDS did.
Consider Hebrew 5: 4 And no man taketh this honour unto himself, but he that is called of God, as was Aaron.
And Amos 3:7
7 Surely the Lord God will do nothing, but he revealeth his secret unto his servants the prophets.