The handwritten document was called by "an outside authority" a fabrication and forgery. That is strong language that was published.
These are Round's opinions and he can not be factored into this discussion moving forward. I have shown him to be errant in a number of ways and his credibility in the matter is non-existent in my opinion.
A different matter you discuss:
"What is the evidence that John Smith of Rivenhall between 1404 and his death in 1446 tried to reclaim his heritage? As I understand it, the diary of John Carrington was not found until long after his death. As I understand it, in his lifetime John Smith of Rivenhall never called himself anything other than .... John Smith."
To say this is to say that the Henry Smyth of Ashby Folville, whose heirs were the Nevills of Holt, had in his family a forger, or at least someone willing to hire one. I don't think this argument holds water as the Smith (of Rivenhall)/Nevill kinship is upheld in a cited will.
Show me someone other than Round (or a Round-ite) that calls the original document a "forgery". I think it would be an excellent academic exercise to compare the language of the handwritten document to others of the period. Any volunteers? I think this is beyond my scope.
Regarding the lineage to Sir Mychael of Carrington:
"This pedigree was copied 1st September, 1870, from a large sheet of parchment
in the Charter Chest of the Nevills of Holt, by A. J. Horwood, Assistant
under the Keeper of the Public Records. Its title is—" The Pedigree and
Exploits in Foreign Countries of John Carington, Armiger, as related by himself
to the year 1404."
The first part consists of a blazon of fifteen shields of arms in colours
belonging to his ancestors and their alliances.
' Then follows a quaint pedigree commencing with " a belsire ycleped
Sir Michael Carington, whome sometyme was standard berer of King Richarde
the first in the holley land."
This starts on page 72 of Copinger's book. "A belsire ycleped..." translates to "A grandfather named..." If the descent from Sir Mychal of Carrington is correct, the relationship to John Smyth (the author) would actually be 3x-g-grandfather.
Reposting of requested citation:
[From] a book titled "War and Society in Medieval Cheshire, 1277-1403" by Phillip Morgan. He mentions:
"Indentures make frequent reference to these irregular incidence of war in the form of ransoms, booty, and appatis, and clearly suggest that great importance was attached to them by the respective parties. John Carrington was able, albeit modestly and often in monastic guest houses, to live for two years on the profit of a single ransom taken at the battle of Brescia in 1401. Similar incidents of a like character are poorly documented in the surviving Cheshire evidence, and indeed much of our knowledge of the success of the military community comes, paradoxically, from the detail of their own ransoms."
https://books.google.com/books?id=FRzoAAAAIAAJ&pg=PA175&lpg...
I believe the elevation of first Viscounts Carrington to the peerage were an example of this Smyth line reclaiming their heritage. Their heir line (legitimate descendants from Smyths of Rivenhall) died out in the 18th century. Theirs is the coat of arms we have attached to this family on Geni. See pg. 41 of Butterworth's work.
Unfortunately, Butterworth has included the Smiths of Bulcot Lodge. Tsk.