WI: The Low Countries’ Ruling Families Don’t All Go Extinct At Once?

In the 14th century the states of the Low Countries went through several dynastic changes that eventually resulted in the Valois-Burgundy inheriting everything.

These are the ones I know about:

The county of Hainaut: Willem IV, Count of Hainaut was married to Jeanne, eldest daughter of the duke of Brabant. They had one child, but since I can’t find dates for his birth or death I imagine he joined the ranks of numerous royal babies of the time who died in infancy. When Willem died, the counties of Hainaut, Holland and Zeeland passed to his sister, Margaretha, who was married to the Bavarian Holy Roman Emperor, Ludwig IV. Her eldest son got into a succession fight with her leading to the first Hook and Cod Wars. Despite English help from her brother-in-law, Edward III, she was still defeated by her son, and forced to resign some titles to him. The Wittelsbach-Straubing line then ruled the three counties until Willem VI, Count of Holland died. Then we had Hook and Cod Wars Part 2, Electric Boogaloo between Willem VI’s daughter, Jacqueline/Jakoba and his brother, Jan III. However, neither of them left surviving/legitimate issue, and the counties passed into Burgundian hands.

The (free) county of Burgundy: The last count of Burgundy, Robert, was betrothed at some point to the youngest daughter of King Edward I, Eleanor. However, both of them died before the wedding could take place, and as a result, the countship of Burgundy ended up passing to his sister, the disgraced and repudiated queen of France, and thence united with the duchy of Burgundy proper by her daughter’s marriage to Duke Eudes IV, the line running out with Philippe of Rouvres.

The duchy of Burgundy: Philippe of Rouvres died after emulating his father in falling from/being thrown from a horse. However, unlike his dad, he did so without leaving any children, which left both the duchy and his widow to the first Valois duke of Burgundy, Philippe II.

The county of Holland and Zeeland
: The last count of Holland, married to a daughter of Edward I, Elizabeth of Rhuddlan, died with no issue. The county then passed to his relations via his great-aunt, the counts of Hainaut.

The duchy of Brabant
: Jean III, duke of Brabant, had three sons which all predeceased him. The eldest of whom was engaged, first to Isabella of Woodstock (Edward III’s daughter) and then to the king of France’s daughter (Jeanne, later queen consort of Charles II of Navarre), whilst the second was engaged to Jeanne de Bourbon (future queen of France). Neither of these marriages were ever ratified on paper and the duchy of Brabant passed to Jean’s oldest daughter, and on her death, to his second daughter, Marguerite, countess of Flanders and her issue.

The county of Flanders: Louis II de Male, Count of Flanders was the last of his line. Originally betrothed to Isabella of Woodstock, he married Marguerite of Brabant. His only daughter, Marguerite, originally mooted as a bride for Edmund of Langley (fourth son of Edward III), married first to Philippe I of Burgundy (a.k.a. Philippe of Rouvres), and after he fell out of the saddle, to his cousin and successor, Philippe II of Burgundy, the first Valois duke of Burgundy.

Now, that’s a basic overview, and I didn’t include some of the states (and I might have gotten some names or regnal numbers wrong), but you get the idea. Valois-Burgundy sort of inherited everything by fortuitous marriages. Burgundy seemed to inherit many of these territories by mere luck of the draw (Louis de Male had two legitimate sons, Charles and Pierre (died in 1376), but both predeceased him); same goes for the Avesnes in Hainaut and Jean III of Brabant), a sort of proto-marry happy Austria (or Burgundy, as the case may be).

But what if they hadn’t? Or rather, the houses mentioned above don’t all go extinct within a hundred years (Holland and the Franche Comté being first on the list, Jakoba of Bavaria adding the last piece of the Burgundian puzzle, give or take a hundred years later). How might the Low Countries as we know them develop differently? Would Burgundy still come out on top? Or might another state play the unifying role?
Excluding the non low country Burgundies, the actual low countries would probably experience some sort of conquest.
The owner of Brabant has a claim to the defunct Duchy of Nether Lorraine and if strong would seek to reinstate it.
I'm wondering what would happen if only Holland, Hainut, and the free county of Burgandy had their surviving dynasties.
Excluding the non low country Burgundies, the actual low countries would probably experience some sort of conquest.
The owner of Brabant has a claim to the defunct Duchy of Nether Lorraine and if strong would seek to reinstate it.

Cool, do you think by force or by marriage or a combo of the two.

Interestingly enough, one of the bastard lines that descended from Louis de Male had a son in the mid-1450s that married to a bastard granddaughter of Philippe III of Burgundy, and then their son married another illegitimate Burgundian descendant.

I'm wondering what would happen if only Holland, Hainut, and the free county of Burgandy had their surviving dynasties.

Well, the last independent count of Holland married a daughter of Edward I, but died soon after. If he'd left her pregnant with a male heir it could make for fun times.

Hainaut seems to be the easiest, since the last Avesnes count actually had a legitimate son, that son just died young. The Free County IDK what killed the last independent ruler, but he was like 15 when he died, so theoretically he could live long and prosper.
Say the duke of Brabant's son, who is betrothed to Jeanne de Valois or Jeanne de Bourbon (OTL queens of Navarre or France respectively) were to survive, and marry said princess. I can't find any info that Charles V of France was ever betrothed to anyone else before he married Jeanne de Bourbon. But I would think that Jeanne (who if I'm not mistaken is responsible for the introduction of the insanity that plagued Charles VI and Henry VI) not marrying into the French royal line could have major effects on the 100 Years War - most notably in that an alt-Charles VI isn't slightly bonkers, and may have a better control over his country. And who cares if the duke of Brabant (Jeanne's son) is kinda nuts and thinking he's made of glass or whatever (well, obviously besides the Brabantians themselves), most likely it just goes down as a slightly amusing anecdote in the local history books. What do you guys (@Janprimus, @pompejus en kie) think?
Mental note: if sent back in time, do NOT marry any daughters of an English Edward, and if forced to, invent the bicycle right quick.
Still debating the question of a marital alliance between England and the Low Countries, but not quite related to the OP.

Edward I's sons, Alphonso and Edward II were both engaged to Netherlandish girls at a point (Alphonso to Margaretha of Holland; Edward II to Philippa of Dampierre), what might the results be of either of these marriages? Alphonso's kids would have a claim to the Scots' throne through the counts of Holland; and Edward II marrying someone else means no French claim for Edward III. But what else? Please discuss