Is the Nomen Sacrum ΙΣ Merely a Transliteration of אִישׁ?

We start with the first example:

Ἰώβ = איוב

The problem here is that the while the אי is transformed into Ἰ the modern Greek pronunciation of Ἰώβ isn't quite right, akin to our English word 'of.'   The next example is:

ήτα =  איטא (Jastrow p. 47)

We have already established that by means of itacism that ήτα was pronounced 'ita' at the time of Jesus in the Middle East.  I have avoided mentioning the other examples of this phenomenon.

Next, we have the Persian king:

Ἰσδιγέρδης =  איזגרא(p. 46)

Then there is the famous 'boot shaped' region:

Ἰταλία = איטליא (Jastrow p. 47)

Then there is the political term 'citizens with equal rights':

ἰσοπολιτεία = אספלטייה (Jastrow p. 53)

and also 'worthy, fit, wealthy':

ἰχανός = איקנוס (Jastrow p. 54)

This by no means scratches the entire list but I think demonstrates that  אִישׁ might well stand behind the nomen sacrum ΙΣ.  There is certainly nothing stopping it from a linguistic standpoint.