During the Hundred Years War England had many chances to take over France but did not. There was a time when the English destroyed the French army and slew nearly all of the nobility. Another time when they captured the French King himself. They even had free reign in in the French Capital but wanted to do things traditionally instead of taking the French throne by force.
I just can't seem to understand why England and it's kings throughout the war did not just take and annex the whole of France. It seems like they were content with simply raiding and 'playing war'.
If I was king of England at the time then I'd of slain the French king and nobility then forcefully claim the whole of France, rename all French city and village names to English names, and setup my sons and family members as govenors of the newly annexed land.
Maybe I'm not looking at the full picture but I thought the point of war is to slay your enemies and take their land. Seems like England and France went to war but at the end of the day still recognized and respected each other's sovereignty.
Too many computer games I'm afraid, war and politics are never quite as easy as simply cutting off the head.
At any rate your proposed attempt of cultural genocide and creation of familial viceroys would go down like a lead balloon with both the French and English aristocracies alike. You should remember that a king ruled with consent and common accord of the bulk of his nobility - when that consent evaporated the ruler tended to be rendered impotent. Thus it also remains important to respect the 'rules of the game' (such as not murdering prisoners when there is no chance of escape, respecting agreements of ransom, etc.) to ensure that your nobility will respect them in regard to your realm.
The Hundred Years War was not just a war between the English and French monarchs, it was also a civil war which ravaged France and played, especially in the first part of the fifteenth-century, upon the murderous rivalry of the Armagnac and Burgundian factions. Had the Dauphin Charles (later Charles VII) not been implicated in the assassination of Jean the Fearless in 1419 it seems unlikely that the Burgundians would have supported the English claim so readily. If the English were rapacious and murderous then they could not acquire the support of Continental allies to further their conquest. It was the territorial ambitions of the duke of Bedford, then regent to the young Henry VI, which soured the relationship between England and Burgundy and allowed Charles VII to begin negotiations with Philip the Good at Arras in 1435 and thus begin the end of England's practical presence on the Continent in the Middle Ages.