Apple Pie, I have to disagree with your conclusion based on many factors not the least of which is how Trinitarians have redefined echad and yachad. I also disagree based on Scripture alone. I also disagree based on my research into Jewish sources for the meaning of Hebrew words. You see Apple Pie trinitarian scholars are divided over how The Theological Dictionary of the New Testament has come up with a definition for those two words that are in total disagreement with any good Hebrew lexicon.
Now Googles has already tried to use The Theological Dictionary of the New Testament on this thread, which I have countered twice and until Googles is willing to address the rebuttal as well as explain the plain language meaning of the Scriptures I posted to continue to site a source neither many trinitarian scholors or I do not recognize as either definitive or accurate based on the above reasons to continue to use that source is not only redundant it is non-productive.
When used as an adjective that modifies a noun echad is in Hebrew the cardinal number one. When used as transitive verb it can mean "to unite, unify, combine, join".
Now is Moses thought of God as a triune God then Moses screwed up with the use of all the first person singular pronouns used when God is speaking and this also applies to the prophets.
Also your appeal to elohiym being plural is disproved in Scripture since elohiym is translated as "god" in over 40 places. Elohiym is an irregular noun just as deer and sheep are in English. Also Jews and many trinitarian scholars view not only the few occassions where God uses plural pronouns for Himself but the plural nouns used for God as an indication of as plurals of majesty.