Yeah, that's what I was alluding to with that final sentence.Does strike me that a descendent of a half brother of Henry VII could well be seen as a good match for a future *Mary I or *Elizabeth I
I must admit that I was a bit uncertain as to what 'John's' marital prospects would be like. He's well-connected and has prestigious ancestry, but his own worldly prospects would be relatively humble- his father was a mere knight and not particularly well-endowed with land, after all.It would seem likely that if Margaret Beaufort and Stafford had a son, 'John?', in the 1460s he would be available to be engaged to an ally of the Staffords or the Stanleys pre-1483, when Thomas Stanley was seen as a loyal Yorkist and ally of Edward IV - who Margaret was ostentatiously loyal to in the 1470s, while trying to get Edward to recall her eldest son Henry Tudor from Brittany. (Edward is supposed to have offered HT the hand of his eldest daughter Elizabeth to lure him back, but this might have been a trap to get Lancastrian pretender HT in his hands and into the Tower or safely married off to a low-status bride and 'disqualified' as a threat instead; he was devious enough.) Thomas Stanley was a long-term Yorkist, though as became well known a selfish and unreliable character, and had deserted his brother-in-law and first patron Warwick in 1471 to back Edward as E invaded England; Edward would probably have used a younger son of Margaret Beaufort (son or stepson of Stanley) as yet another pawn in his intricate marital alliance plans and married him off to some useful noble ally's daughter, choosing a reliable Yorkist to 'control' him. Possibly a junior and Yorkist relative of a rising dynasty dependant on Edward for patronage - a Herbert from SE Wales (related to E's late strongman there who Warwick had killed in 1469, William Herbert Earl of Pembroke), as a local noble semi-neighbour of the Lancs Stanleys, a junior Howard , or a Yorks or Lancs ally of the Stanleys. if the young 'John Stafford' was not married but just engaged as of 1483-5, Richard III then could have used him as bait to lure in another potential noble ally and dangled preferment in front of him to get him to keep an eye on his ex-plotter mother and the distrusted Thomas Stanley. If 'John' was not married as of post-1485, Henry VII and Margaret would have used him as a link to some useful Lancastrian or ex-Yorkist family as in OTL Margaret used Henry's wife's sisters - eg the Welles or the Howards?