The Watchers and Giant Trees

The Mercer Dictionary of the Bible makes a distinction between the Grigori and the fallen angels by stating that in fifth heaven, Enoch sees "the giants whose brothers were the fallen angels." The longer recension of 2 Enoch 18:3 identifies the prisoners of second heaven as the angels of Satanail. Watcher (Aramaic עִיר ʿiyr, plural עִירִין ʿiyrin, IPA ʕiːr(iːn); Theodotian trans: ir; from the root of Heb. ʿer, "awake, watchful"; Greek: ἐγρήγοροι, transl.: egrḗgoroi; Slav transliteration, Grigori, "Watchers", "those who are awake"; "guard", "watcher" is a term used in connection with biblical angels. Watcher occurs in both plural and singular forms in the Book of Daniel (4th–2nd century BC), where reference is made to their holiness. The apocryphal Books of Enoch (2nd–1st centuries BC) refer to both good and bad Watchers, with a primary focus on the rebellious ones. In the Book of Daniel 4:13, 17, 23 there are three references to the class of "watcher, holy one" (watcher, Aramaic `iyr; holy one, Aramaic qaddiysh). The term is introduced by Nebuchadnezzar who says he saw "a watcher, a holy one come down (singular verb) from heaven." He describes how in his dream the watcher says that Nebuchadnezzar will eat grass and be mad and that this punishment is "by the decree of the Watchers, the demand by the word of the Holy Ones" ... "the living may know that the Most High rules in the kingdom of men." After hearing the king's dream Daniel considers for an hour and then responds: And because the king saw a watcher, a holy one, coming down from heaven and saying, 'Chop down the tree and destroy it, but leave the stump of its roots in the earth, bound with a band of iron and bronze, in the tender grass of the field, and let him be wet with the dew of heaven, and let his portion be with the beasts of the field, till seven periods of time pass over him,' this is the interpretation, O king: It is a decree of the Most High, which has come upon my lord the king, that you shall be driven from among men, and your dwelling shall be with the beasts of the field. You shall be made to eat grass like an ox, and you shall be wet with the dew of heaven, and seven periods of time shall pass over you, till you know that the Most High rules the kingdom of men and gives it to whom he will. 

Nebuchadnezzar could certainly be compared to Cain being expelled from the  Garden to toil in the fields with the beasts.  Were these giant trees once a means for giants aka "Watchers" to come down from the heavens?  Was this the inspiration behind Jack and the Beanstalk?