Does the Silmarillion Contradict Third age History?

[Gilrandir]

The Silmarillion is actually a quintuple tale: the Ainulindalë and Valaquenta; the Quenta Silmarillion; the Akallabêth; and The Rings of Power and the Third Age. The first two (the story of the creation of the Ainur and accounts of the Valar) would serve as an intro to--- the Quenta Silmarillion (part I of the trilogy...the story of the Silmarils); the Akallabêth (part II of the trilogy...the rise and fall of Númenor); and finally, part III, the Making of the Rings of Power and the forging of the One Ring.

A trilogy, yes?

No, then it is quintilogy.

But I would not try to describe it by any term that would count the number of books it consists of. It is a compendium of narratives that never reached its complete form and was in constant tranformation while Tolkien lived.