So Jacob said to his household and to all who were with him, "Rid yourself of the alien gods in your midst, purify yourself, and change your clothes. (Genesis 35:2 NJPS)
Jacob's instructions which are directed to everyone, would apply to Rachel, who had stolen her father's household idols which her father called gods:
While Laban had gone to shear his sheep, Rachel stole the household idols (הַתְּרָפִ֖ים) that belonged to her father. (Genesis 31:19 NET)
And now you have gone away because you longed greatly for your father's house, but why did you steal my gods (אֱלֹהָֽי)?” (Genesis 31:30)
It is clear Rachel stole Laban's physical idols (teraphiym - תְּרָפִים) which Laban called gods ('elohiym - אֱלֹהִים). The exact nature of the idols and Laban's gods are not described, but it is clear they were plural and likely represented different gods. Jacob's instruction continues to refer to the idols as gods and so the objects, hence gods were plural and a reflection of polytheism. In this case "gods" refers to individual (and so different) idols meant to represent individual (and so different) gods. The term 'elohiym used in Genesis 35:2 then certainly means different gods with different attributes and/or powers.
The notion of a "plurality of persons within themselves" (in contrast with a simple plural) would depend on the specific beliefs associated with a particular god. It is speculation, but the fact the same god or goddess could be depicted with a different idol, does suggest a plurality of identities, at least in the mind of idol maker or worshiper. In other words, if the same god or goddess could be represented by a different idol, it is not unreasonable to assume a different idol was a representation of a different "personage" of the deity.
Extra biblical material say Abram's father was a idol maker. So imagine shopping for an idol and choosing from different appearances of the same god or goddess. Likewise the use of idols or objects in worship could indicate a plurality of personages of the same deity. For example, the worship of Asherah was done both with idols and with groves, presumably appealing to a different aspect of the same deity. Finally polytheism is highly syncretic and the same deity takes on or is given a different personage by a different group. This is obvious across different cultures and as such possible within the same group. For example, as different people were traveling with Jacob and apparently others beside Rachel had their gods, different idols for the same god would be an indication of a plurality of belief about the god within the same group.
Now I know that the LORD is greater than all gods, yes, by the result of their very schemes against [the people]" (Exodus 18:11 NJPS)
This statement is made by Jethro, a Midian priest. About the use Jeffrey H. Tigay says:
Now I know: In a further fulfillment of the LORD's aim that all come to know His name and acknowledge Him (see 5.1-6.1n; 62.n; 14.4; 15.3), Jethro recognizes His superiority, though he does not renounce other gods (contrast Naaman in 2 Kings 5.15, 17). The Torah does not expect Gentiles to become monotheists (see Deut. 4.19), only to recognize the LORD's superiority and authority when He asserts it, as in the case of Egypt. The ideal of universal monotheism first appears in the classical prophets (Jer. 16.19-20; Zech. 14.9) Neither the prophets nor Jewish tradition call for conversion to Judaism of Gentiles, though latter Jewish tradition - characteristically reading the Bible through the prism of the prophets - believed that Jethro did abandon idolatry (Exod. Rab. 1.32) and, going even further, became a Jew (Tg. Ps-J. Exod. 18.6, 27; Tanh. Buber Yitro, 5)
First, it is worth noting that at this time in history, Judaic monotheism was not what it was later, say in the Second Temple period. Second, there is a contrast with Genesis, as the gods are gods. There may have been idols associated with them, but there is never mention as such. So the Egyptian magicians were able to duplicate the first two signs by magic (presumably by their gods) and the LORD executes judgement on all of the gods (אֱלֹהֵ֥י) of Egypt (Exodus 12:12). In other words, from Jethro's and the Egyptian's perspective, and likely Moses as well, the gods are real entities described using the word 'elohiym. As with Laban's gods, there are no Biblical details given other than they are called gods.
With regard to a plurality of personages, the Egyptian God Hathor offers some insight:
Hathor (Ancient Egyptian: ḥwt-ḥr "House of Horus", Greek: Ἁθώρ Hathōr) was a major goddess in ancient Egyptian religion who played a wide variety of roles. As a sky deity, she was the mother or consort of the sky god Horus and the sun god Ra, both of whom were connected with kingship, and thus she was the symbolic mother of their earthly representatives, the pharaohs. She was one of several goddesses who acted as the Eye of Ra, Ra's feminine counterpart, and in this form she had a vengeful aspect that protected him from his enemies. Her beneficent side represented music, dance, joy, love, sexuality and maternal care, and she acted as the consort of several male deities and the mother of their sons. These two aspects of the goddess exemplified the Egyptian conception of femininity. Hathor crossed boundaries between worlds, helping deceased souls in the transition to the afterlife.
Hathor was often depicted as a cow, symbolizing her maternal and celestial aspect, although her most common form was a woman wearing a headdress of cow horns and a sun disk. She could also be represented as a lioness, cobra, or sycamore tree.
Indeed, this goddess had multiple "personages" and was represented by different idols.
First, based on what is known, it is reasonable to understand 'elohiym in these two contexts means both multiple entities and an individual entity with different idols and representations of their different "personages." In some cases the gods were real entities but likely in all cases, the human understanding of a god or gods was just that: a product of the human mind. As many deities and religious beliefs were subsumed or assumed by neighboring or conquering cultures, the human understanding was undoubtedly one of multiple personages for the same entity.
Second, the use of 'elohiym to describe other than the God of Israel, is of no value in identifying the meaning and/or character of the 'elohiym of Israel. The basic tenet of Scripture is a positive revelation of God to man and "what is not god" is useful only to point out the foolishness of other gods. Beyond that "what is not god" is of little, if any, use in stating "what is God."
After recognizing a plurality of personages is present in the gods of Laban (Genesis) and the Egyptian gods (Exodus), the question was modified, adding Moses and Dagon. This addition addresses that change:
Dagon, the national god of the Philistines was widely worshiped throughout the Near East:
He was a West-Semitic god, probably of Amorite origin. His land is Syria, from the Euphrates to the Levantine coast. The evidence for the cult of Dagon begins in the third millennium Mesopotamia and continues uninterruptedly for near two thousand years.
When the Philistines settled in Canaan, they originally worshiped a female goddess which morphed into the worship of Dagon:
…originally worshipped a “Mother Goddess” of Aegean-Anatolian type. A scrutiny of the syncretisms prevailing in the ancient world has revealed a close parallel between Dagan, the Semitic earth and grain god, and the “great mothers” of the Aegean-Anatolian realm, who were essentially also deities of the earth and everything that grows and lives on it. The functional correspondence that explains the establishment of this syncretism (despite the sexual difference), was probably further intensified by a phonetic resemblance in the names of the epithets of the two deities.
So not only is it fair to say Dagon had a plurality of personages: "he" was originally "she" and during the "transition" some would still see Dagan in her original person while others in his new one (or perhaps both depending on the situation).
On the surface it seems unreasonable to suggest multiple personages for Moses. The reader knows and the Israelites knew Moses was not a god. Yet the question is what did Pharaoh believe about Moses? What is the god YHVH made him to be to Pharaoh (cf. Exodus 7:1)? At this point we can only speculate what Pharaoh might have believed about Moses. There may have been multiple personages or not.
What can be said for certain is since Pharaoh believed in multiple gods, Moses was "just another" of Pharaoh's gods. Judging from Pharaoh's response, it is fair to say Moses wasn't much of a god in Pharaoh's eyes. I think there are two possibilities. One, it is possible the LORD's point in making of Moses into "a god" for Pharaoh, was to show Pharaoh's complete disdain for all gods or how he thought of himself in relation to "the gods." Two, it is possible the LORD made Moses a representation or a type of one of Pharaoh's existing gods. In other words, Moses was not 'elohiym; rather Moses was just a human manifestation of one of the Egyptian gods Pharaoh believed existed in the spirit realm. In any event, there is no sound conclusion to be made about 'elohiym based upon what Pharaoh thought. Biblically speaking, Moses as 'elohiym should be limited to a judge not a god.
1. Jeffrey H. Tigay, The Jewish Study Bible, Edited by Adele Berlin and Marc Zvi Brettler, Oxford University Press, 2004, p. 143-144
3. Itamar Singer, Towards the image of Dagon, the god of the Philistines, Syria. Archéologie, Art et histoire Année 1992 69-3-4 p. 437
4. Ibid., p. 450