This table should help show the different usage:
|Jehoshua||in Haggai and Zechariah, while (fit the battle) Jehoshua is restricted to Exodus and Joshua (with a few elsewhere).|
|Jeshua||occurs 30 times in the Hebrew bible, exclusively in Chr, Ezra and Nehemiah.|
|Jehozadak||in Haggai and Zechariah, as well as Chr.|
|Jozadak||found in Ezra and Nehemiah|
|Jehonathan||mainly in Samuel (61 of 74)|
|Jonathan||used sparsely (12x including 5 in Esther).|
|Jehoiakim||appears 36 times in Kings, Chr and Jeremiah|
|Joiakim||occurs 3 times only in Nehemiah.|
Both Haggai and Zechariah are earlier than Ezra and Nehemiah. Esther is also thought late. What we see is not a sudden stop of using the long form but a transition from long to short forms. We have the same person, Yeshua the high priest of the return being called Yehoshua in Haggai and Zechariah, and the short form in Ezra and Nehemiah.
The LXX uses the one form for both Yehoshua and Yeshua, Ιησους; the one form for Yehonathan and Yonathan, Ιωναθαν; similar forms for Yehozadak and Yozadak, Ιωσαδακ and Ιωσεδεκ. The Greek is obviously following the later habit based on the short form.
This very thing, too, still further demonstrates their opinion false, and their fictitious system untenable, that they endeavour to bring forward proofs of it, sometimes through means of numbers and the syllables of names, sometimes also through the letter of syllables, and yet again through those numbers which are, according to the practice followed by the Greeks, contained in letters;– [this, I say,] demonstrates in the clearest manner their overthrow or confusion, as well as the untenable and perverse character of their [professed] knowledge. For, transferring the name Jesus, which belongs to another language, to the numeration of the Greeks, they sometimes call it “Episemon,” as having six letters (i.e. Ἰησοῦς because it has six letters), and at other times “the Plenitude of the Ogdoads,” as containing the number eight hundred and eighty-eight (i.e. the numerological value of Ἰησοῦς). But His Greek name, which is “Soter,” that is, Saviour, because it does not fit in with their system, either with respect to numerical value or as regards its letters, they pass over in silence. Yet surely, if they regard the names of the Lord, as, in accordance with the preconceived purpose of the Father, by means of their numerical value and letters, indicating number in the Pleroma, Soter, as being a Greek name, ought by means of its letters and the numbers, in virtue of its being Greek, to show forth the mystery of the Pleroma. But the case is not so, because it is a word of five letters, and its numerical value is one thousand four hundred and eight. But these things do not in any way correspond with their Pleroma; the account, therefore, which they give of transactions in the Pleroma cannot be true.
Moreover, Jesus, which is a word belonging to the proper tongue of the Hebrews, contains, as the learned among them declare, two letters and a half, (ישו) and signifies that Lord who contains heaven and earth; for Jesus in the ancient Hebrew language means “heaven,” while again “earth” is expressed by the words sura usser. The word, therefore, which contains heaven and earth is just Jesus. Their explanation, then, of the Episemon is false, and their numerical calculation is also manifestly overthrown. For, in their own language, Soter is a Greek word of five letters; but, on the other hand, in the Hebrew tongue, Jesus contains only two letters and a half. The total which they reckon up, viz., eight hundred and eighty-eight, therefore falls to the ground. And throughout, the Hebrew letters do not correspond in number with the Greek, although these especially, as being the more ancient and unchanging, ought to uphold the reckoning connected with the names. For these ancient, original, and generally called sacred letters of the Hebrews are ten in number (but they are written by means of fifteen), the last letter being joined to the first. And thus they write some of these letters according to their natural sequence, just as we do, but others in a reverse direction, from the right hand towards the left, thus tracing the letters backwards. The name Christ, too, ought to be capable of being reckoned up in harmony with the Aeons of their Pleroma, inasmuch as, according to their statements, He was produced for the establishment and rectification of their Pleroma. The Father, too, in the same way, ought, both by means of letters and numerical value, to contain the number of those Aeons who were produced by Him; Bythus, in like manner, and not less Monogenes; but pre- eminently the name which is above all others, by which God is called, and which in the Hebrew tongue is expressed by Baruch, (בָּרוּךְ ??) which also contains two and a half letters. From this fact, therefore, that the more important names, both in the Hebrew and Greek languages, do not conform to their system, either as respects the number of letters or the reckoning brought out of them, the forced character of their calculations respecting the rest becomes clearly manifest.[AH 2.24.1,2]
How's your fourth century conspiracy, now? Irenaeus is actually attacking the use of Greek to understand Jesus and arguing for the Aramaic basis to the tradition. As I noted in another post I strongly suspect that Irenaeus original wrote in Aramaic.
Harvey agrees with my identification of yeshu as the two and a half letter name of Jesus (p. 336). He also points to a marginal note that somehow made its way into the sentence in the oldest manuscripts – 'sion' which he takes to be a misunderstanding of a note which spelled out the value of yeshu (i.e. shin = 300, yod = 10, vav = 6). This strongly implies to me again that the original text was written in Aramaic.