I have to disagree with your view. Even though "The Princes in the Tower" were officially disinherited by an act of Parliament, Royal History and Richard's prior historical action would tend towards Richard III having seen a necessity here. We are talking about the "War of the Roses" time, and no King's head could rest peacefully, no matter how legitimate (or not).
Edward V, was the recognized and legitimate successor to his father, until deposed by Parliament under the control of Richard, two and a half months later. By most accounts of likely death, he is the shortest lived King of England. As for Henry Tudor (Henry VII), he was in Brittany until his re-entry into Wales a year later and given that Richard would have been insane to not have assured himself that the 'Princes' were guarded by his most loyal men, it is difficult to see how he would have engineered their deaths UNLESS they were still alive when he emerged the victor at Bosworth Field in 1485. Since that was almost a year and a half since they were last seen alive, I deem it unlikely.
Interestingly enough, Richard III may again be following his nephews in history. In 1674, a wooden box containing two small human skeletons was found buried close to the White Tower in the Tower of London complex. The siting of the grave seemed to match where Sir Thomas More (Saint Thomas More RC) put it in his "History of King Richard III". Charles II had these bones placed in an urn and interred in Westminster Abbey. In 1933, these bones were examined and then reinterred. It was found that many bones were missing and the urn included some animal bones as well. Photographs of the bones indicate two individuals, 11–13 and 7–11 years old with nothing to disclose gender. DNA analysis could do so and if Richard III is so analyzed then there should be a strong match to such near kin, if that is who they were.
The current queen will not allow the bones of the children to be disinterred so that modern dating methods can be used. I have seen the dental records made in 1933 and they are very interesting. Some say the young (unanointed) king died from a disease of the jaw and the records do show signs of serious illness.
Most Ricardians tend to think that the Duke of Buckingham (who had charge of the kiddies, I believe) killed them - without Richard’s knowledge. I, myself, don’t know. All I know is that at this point in history, we have no proof Richard did away with them.
Richard III took the throne over Edward V, not by deposition, but by virtue of being of age. Given that Edward IV was likely poisoned by the Lancastrians, it was a legitimate fear. Both Richard and Edward were Yorkists! Having Richard on the throne would protect the kids.
The problem for Henry VII, is that his wife was junior to Edward V and his younger brother Richard. With them out of the way, Elizabeth of York became the senior claimant.
Edward IV died in 9th April of 1483, from a protracted illness, possibly poisoning. Edward V in his will was designated his heir, while the then Richard of Gloucester (later Richard III) was designated the Protector. Edward V was never coronated - Richard took over as King, 22nd of June. The Princes were last seen that summer, but we don’t know when they died.
Follow with me here.
December of 1483 - Henry Tudor agrees to marry Elizabeth of York.
Richard III dies in Bosworth in 22 August of 1485, after just two years on the throne.
Henry takes the throne and then states that the princes were murdered in the tower, and blames Richard III. Of note - he did not state this until after he acceded to the throne after Bosworth. No bodies were produced, nothing. It is possible that the boys were still alive in the tower when Henry VII came to the throne in August of 1485, just two years after the accepted date of their death.
Henry VII would have been 26 in 1483, and 28 when he came to the throne. Elizabeth would have been 17 in 1483.
So, it all fits. Poison Edward IV. Pledge to marry his oldest daughter the year later. Defeat, and kill Richard III, in battle. Kill Edward V and Richard in the tower, before you marry their sister, after Bosworth. Claim, after Bosworth that the boys were missing and that Richard III was responsible.
Ir all fits together, and it makes what happened in this extraordinary 3 year period make sense.
There was no motivation for Richard to kill the princes that his brother left in his will for him to protect. There was every motivation for Henry VII to kill them after his accession.