It should be remembered when analyzing any claim regarding the date of a text that dating a document is much like any other exegetical task in that the exegete brings with him or her certain presuppositions which often “bend” the data toward an expected result.
This is just as true in assigning a date to an archaeological element as it is in assigning a meaning to a Biblical text.
It is a phenomenon called “archaeological bias.”  Since the genre is a speculative approach, guessing at what a famous figure what have to say on a matter, it is generally categorized under the meta-genre of fiction.
Pseudepigraphical works are not included in the Jewish canon, nor in the Christian canon, but these do not comprise all the non-canonical writings of the time period. Stone lists examples of writings from this genre in his Jewish Virtual Library article.
The Hebrew plural participial forms for I-nun verbs, however, include neither of the forms נְפִלִים and נְפִילִים as possibilities.
The masculine plural passive forms required for the rendering of “fallen ones” (across the various (in the niphal stem) have also been proposed, but the same conjugation issues found in attempting to use naphash equally plague those three roots.
 It is not an absurd jump to allow for an Aramaic word to occur in the Torah, since we have other words already well-established as being loanwords throughout the Torah — most from Egyptian, admittedly, but we do encounter a clearly Aramaic term in the Hebrew text of Genesis , i.e.
the place-name יְגַ֖ר שָׂהֲדוּתָ֑א (Yegar Sahadutha; i.e.  Other issues with this “demon-spawn” view are listed on page 1 of the summary sheet found provided below.
“stone-pile of testimony”), which is the much simpler גַּלְעֵֽד in Hebrew. Girdlestone’s contribution to the confusion is his assertion that is a genre popular from the 2nd century BCE to the 8th Century CE characterized by the attribution of the name of a well-known figure from the past to one’s work in order to explore what that person might have said on a subject he or she had never addressed.
 Pseudepigraphy (false attribution) was a literary device that was well understood by the audience, and in most cases no deception was intended by it (though modern audiences can tend to be confused by the device).
 The principal deviant from this view is the Kabbalistic (Jewish mysticism) text the Zohar (a). Kaiser’s observation in regard to the Greek translations is that of the several variant Septuagints, only one (the Alexandrian recension) inserts “angels” into its translation of the text.
Rahlf’s authoritative critical edition shows that the rest do not.
In fact, despite the Ethiopic insistence that is Scripture, the Amharic Ethiopian Orthodox Bible also presents as fact the Sethian view of the בְּנֵי הָֽאֱלֹהִים (“sons of G-d”).