Utterly irrelevant. We know Simonides used real people as his alter egos. Your arguments amount to nothing, compared to the weight of evidence McGrane introduces. The fact is no-one matching the criteria of Simonides has ever been located.Read.more carefully.
Later nineteenth century is the 1860s library entry.
1,000 times more consequential are the two 1841 entries, connected to Simonides, contiguous and the same manuscript copied.
McGrane is an absolute disaster on the catalogue entries.
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Monk titles are subject to change over time.