None of these books relate to law; and the better opinion seems to be that there were two Tribonians, apparently contemporaries, though possibly some of the attributes of the jurist have been, by a mistake of the compilers or transcribers of the Lexicon of Suidas, extended to the man of letters of the same name.
For reasons suggested partly by the study of Semitic inscriptions, partly by comparison of passages occurring twice within the Old Testament, and partly by a comparison of the Hebrew text with the Septuagint, it is clear that the authors of the Old Testament (or at least most of them) themselves made some use of these vowel consonants, but that in a great number of cases the vowel consonants that stand in our present text were inserted by transcribers and editors of the texts.
The oldest texts belonging to the heroic cycle are not preserved in any MS. before 110o, and though the sagas were certainly committed to writing several centuries before that date, it is evident that the monkish transcribers have toned down or omitted features that savoured too strongly of paganism.
Enumerators, indexers and transcribers can often misspell a name; Pearce can become Pierce, Merill may be Merril or Merrill, and Lewis may be Louis.
Remember that transcribers can make mistakes, so don't rely on only one record for a date or spelling of a name.
