Giving the Protestant Lion of the North 20 more years would almost certainly have butterflied beyond recognition the development of Central Europe. While the maintenance of a Swedish Baltic Empire was probably not feasible in the long run, a surviving and successful Gustav Adolph would have most likely led to a permanent division between Protestant Northern Germany and the Catolic Hapbsurg and Wittlesbach south.
As it pertains to Sweden and empire, could a surviving Gustav Adolph have given strength to Swedish colonial ambitions elsewhere? Like in the Americas and East Indies, perhaps Africa?
...a surviving and successful Gustav Adolph would have most likely led to a permanent division between Protestant Northern Germany and the Catholic Hapbsurg and Wittlesbach south.
So this here would pretty much be the end of HRE in every aspect and a two new German polities, divided along sectarian lines, north and south.
How would this Hapsburg-Wittlesbach polity fit within the Hapsburg's overall holdings in Europe?
Further, what would be the make up of the norther German polity and who would be the major players there? Hanover-Hesse? Orange-Nassau? Saxony? Brandenburg-Prussia? Some combination of two or more?
The enthronement of local sovereignty created at Westphalia would not have happened.
Who would the butterflies from this effect most?
Would Brandenburg-Prussia be 'strangled in the crib', so to speak, or, by war's end, would they end up perhaps in a better position than OTL? Worse? Same?
I could see the development of a single North German state and perhaps a Wittlesbach ruled SOuthwestern German state, the collapse of the HRE, and the withdrawal of the Habsburgs to their heritary lands and an earlier focus on the Balkans. So giving Captain Gars his 20 years would be a Mothra sized butterfly.
Could this lead to a more concrete union of Wittlesbach and Hapsburg lines? Bavaria and Austria ending up in some sort of union at the head of the Catholic German states, perhaps a larger German speaking component of the Hapsburg Empire?
Further, once power and position is consolidated in the sort of 'Austria-Bavaria', how long before the Austrian Empire turns it's attentions towards pushing the Ottomans off the continent, and could they do it? Is 'All the way to Constantinople' the ultimate goal, or do they draw the line short of that?
Perhaps I should have gone with Gustav Adolph alone for this thread, as it seems his survival leads to the far broader ranging changes between OTL and a hypothetical one where he lives 20 or so more years.
As for the others in the OP. Charles X was already broken, I see little impact there.
Define 'broken'.
Charles X seems like he could have had some effect of the world had he lived another 20 years, or am I missing something here?
...nor do a see a significant impact from William the silent.
Seems to be the consensus, thus far.
Now the case of the English Kings is more interesting. Giving Richard 20 more years at least butterflies away the reign of John Lackland, the James Buchanan of English Kings. Richard would have been able to stand up to if not defeat Philip Augustus so the Anglo-Norman state would have lasted longer, keeping both the crown and the major barons divided in focus between England and Normandy. Whether a longer-lived Richard could have forged a more permanent Anglo-Norman-Aquitane state is questionable, but if he could have annulled his going nowhere marriage, re-married and quickly sired a capable male heir (big if's) he could have delivered to a 16 -18 year single heir the complete Plantagenet domain. In that case, it is more likely that the west of France, especially Aquitaine and Brittany, would not have become French as easily as in OTL, with all the long term butterflies that brings. Otherwise Richard's death brings a succession crisis between Arthur of Brittany and John's heir (OTL Henry III, if he exists or some other TTL heir) and some type of division of the Angevin patrimonies.
Perhaps I should have created a separate thread for Richard I as well!
Very interesting possibilities there.
With Henry V the problem remains that by the 1400's there was a French identity and no single ruler no matter what his capabilities was going to rule England and France.
The brick wall of all Henry V threads, French Identity, strikes once more.
And even with 20 more years his son is still a dithering incompetent. His extra years largely postpones the collapse of the English position in France but does not have long term potential for changes.
What if Henry VI dies at some point during those twenty extra years Henry V lives? Who would Henry's fortunes pass to when he passes in 1442 (given 20 more years)?
At 35/36 at the time of his death, perhaps he and Catherine of Valois have more children and perhaps a more capable heir is produced? Hell, if Henry lives another 20 years for Henry VI to learn from, perhaps he doesn't end up as incompetent as OTL?
A better candidate for significant impact with 20 more years would be Edward, the Black Prince. His survival to become King Edward IV allows his son Richard to mature before becoming King and even if the English position in Aquitaine was not much improved, his survival might well butterfly away the Bolingbroke usurpation and therefore the Wars of the Roses (and Henry V as a King!) and in the long run the Tudors and all that entails. That calls for a timeline but I am not competent to write it.
Yet another figure who probably deserves another thread all their own! (Can't figure out how I forgot him in the OP, then again, I also forgot Gustav Adolph initially, so...)
So, Edward becomes Edward IV in 1377, reigns until 1396 (or so)...could be interesting.