You apparently think “absolutist” means the degree of dynastic security. That’s not what it means when used by historians. It refers to the claim claim by kings that all power and authority, even religious, rests with them, rather than being divided among kings, nobles, towns, bishops.
It was distributed among all the above in the Middle Ages. Kings and some bishops and some towns and some nobles tried to gain more power for themselves. The others resisted. That’s what Magna Carta was about. The nobles appealed to their legitimate authority/power role against the king’s overreaching.
You are talking apples to my oranges. So what if the Tudor dynastic grasp was precarious compared to Charles V’s (you err when you lump France in with Spain—1500s in France was dynastic chaos, far worse than Tudor England). Absolutism has nothing to do with precarious or solid hold on the kingship.
It has to do with the claims made by whoever holds the kingship, claims vis a vis other possible claimants.
It is a simple fact that Henry VIII claimed superiority over the Church in England. That’s royal absolutism.
Neither Charles V nor Philip II in Spain ever, ever, ever, claimed anything like that. De facto Philip controlled a lot of the church in Spain but he did it as an abuse of authority. Henry VIII openly claimed that his having absolute supremacy was right and good.
So did the city council in Zurich.
And that claim and Luther’s granting of authority to reform the church to the prince and all sorts of other Protestant moves were breathtakingly new.
Catholic rulers were moving in the same direction but were not as far along—they had to make these moves under-the-table because the claims violated Catholic beliefs.
The Tudors did not repeal Magna Carta. Elizabeth respected the prerogatives of Parliament and the aristocracy. She was constantly politicking to get the appropriations she needed.
In France, I had the Bourbons in mind. So, by your definition Henry VIII was an authoritarian because he took England Protestant but France was not, even though Richelieu actually made war on the French Protestants. And by your definition Louis IV wasn't an authoritarian King, even though he is universally regarded as such.