One of the stupidest claims made in Trinitarian theology has to be the claim that the Hebrew word echad is a special word which is used for a "compound unity." This idea was popularized by Walter Martin who used the example from Scripture concerning one cluster of grapes. However it is not the word echad which implies a compound unity. It is the word "cluster." A single cluster of many grapes is "1" cluster in any language and there are many grapes in that one cluster.
The stupidity here is that the word "one" in any language is used for compound unities. Compound unities are "categories" or "groups" of multiple things and when we refer to a group of multiple things we all recognize it is "one" group of "many" things. One herd, one flock, one team, one cluster, one constellation all refer to groups of things which can be said to be "compound unities" not because they are qualified by the word "one," or echad, but because we have these words in our many languages to identify "one" group of these things. The Hebrew word echad does not itself ever imply anything but the numeral "1."