The following paragraphs are from Buddhism in Sri Lanka: A Short History, by H.R Perera. They give us a little clue as to what was happening with the writing and compiling of this literature. Three of those paragraphs (the ones about Mahākassapa) may look familiar, as I posted them recently in the thread about Parākramabāhu I here:
I repost them here, along with the other ones from the section, for completeness (the other thread just has those snippets).
Thank you to @RobertK who kindly posted a link to the Saddhammasaṅgaha in that thread, which is a 14th century text that H.R. Perera mentions in the quoted text, and which he used as a source for his information:
2015.50914.A-Manual-Of-Buddhist-Historical-Traditions_text bimala law.pdf (3.5 MB)
the translation is here
R