without waw in Targumim and Peshitta is irrelevant. Targumim basically
follow the spelling of names in the Masoretic Text, and the Peshitta uses
waw when there is an /o/ or /u/ vowel (except for a few specific words).
These texts are governed by rules internal to themselves.
Regards,
Pete
*Dr P. J. Williams, Tyndale House, Cambridge, CB3 9BA, U.K.*