Consider the following coincidences:
1) The Mortimer-York army in 1458-60 was led by the Duke of York, two sons, a brother-in-law and a nephew. Charles I’s principal commanders were himself, two sons and two nephews.
2) Richard of York had four healthy sons, one named after himself who became King. Charles I had three healthy sons, one of whom bore his own name and eventually succeeded him.
3) Richard III was crowned because his nephews (and nieces) were illegitimate, as was James VII/II.
4) Henry of Buckingham’s revolt was apparently coordinated with that of his cousin, Henry “Tudor”, as was James of Monmouth’s with the Earl of Argyll.
5) “Tudor” sought to land in Dorset, which Monmouth actually did.
6) Autumn 1483 and summer 1685 were both exceptionally wet, hindering the revolts.
7) Buckingham and Monmouth both went into hiding but were eventually captured.