The most striking new fact about Marcionite usage brought out by these treatises is that the Syriac-speaking Marcionites used a different transliteration of the name 'Jesus' from the orthodox. The ordinary Syriac for Jesus is [E-WAH-SHEM-YUD] pronounced 'Isho' by Nestorians but Yeshu' by Jacobites, which is simply the Syriac form of the Old Testament name Joshua. This form 'Isho' was used not only by the orthodox, but also by the Manichees. It was therefore a surprise to find that Ephraim in arguing against Marcionites, and certainly in part quoting from their books or sayings, uses the form 'ISU', a direct transcription of the Greek 'IHSOU (or IHSOUS). As it [the Marcionite name for Jesus] is always written [WAH-SEMKATH-YUD], never [WAH-SEMKATH-YUD-ALPHA], I suppose the pronunciation intended is IESU rather than ISU, but I have retained Mitchell's ISU (vol. i. p. li). [D. Mahar, The System of Marcion]
But what if history had it reversed. The Marcionite name for Jesus developed in Aramaic as אישו and then a Greek writer - possibly Orthodox - likened the name to the Greek Ἰησοῦς. The idea that the name of the Stranger god was simply 'His man' i.e. 'the man of God' (Deut 33:1) would explain immediately Paul's interest in two Adams at the end of the Epistle to the Corinthians. It would also explain why Tatian and the Encratites denied the first Adam salvation. The second man (= not 'Adam') was the Lord from heaven, embodied - or 'heralded' - by Moses but something/someone ultimately superior to him. The heavenly high priest, the angel of the Presence.