A-historical isn't the word I would use as there were rare instances of children taking the dynastic name of their mother in European history. An example I can name right away, though it's from the XVIIIth Century, is that of princess Louise Hippolyte of Monaco: she married Jacques François Goyon, count of Matignon but the children took the name of Grimaldi to allow the dynasty to survive. So Matrilineal marriage were possible historically. That being said, they oftened hapenned for a very specific set of reasons, usually to allow the dynasty to survive, and they required an agreement between both families and sometimes their liege lord (in the case I mentionned, the King of France had to give his approval). This in turn explains the rarity of such unions.
There's also the second House of Lusignan- Hugh III of Cyprus took the surname of his mother Princess Isabella of Cyprus rather than his father Henry of Antioch.
In more recent history you have the post-1740 House of 'Habsburg' (which is
really the House of Lorraine, and is
sometimes referred to as Habsburg-Lorraine) and every post-1762 'Romanov' (who are actually the House of Holstein-Gottorp, and are
very rarely referred to as Holstein-Gottorp-Romanov).
There's also the current royal family, with (some of?) Elizabeth's descendants being declared members of the House of Windsor (leading Phil to complain "I am nothing but a bloody amoeba. I am the only man in the country not allowed to give his name to his own children."). Of course Philip uses
his mother's (anglicised) family name of Mountbatten rather than his father's Schleswig-Holstein-Sonderburg-Glucksburg, so I guess that makes him a hypocrite or something.
So Charlie is an agnatic member of the House of Schleswig-Holstein-Sonderburg-Glucksburg (a branch of the House of Oldenburg) whose father uses the name Mountbatten (which is
really Battenberg, which is a branch of Hesse-Darmstadt) but who officially belongs to the House of Windsor (which is
really Saxe-Coburg-Gotha, which is a branch of the Wettins).
That too me would be more realistic than a game that forces you to stick with one dynasty for centuries, when in reality only a handful of dynasties lasted much longer than two or three centuries.
I don't disagree with you, but doesn't that take some of the difficulty out of the game? Wouldn't your system radically reduce the chances of a game over?
I personally just marry any daughters that look like inheriting off to other members of my dynasty. If I don't have any other members of my dynasty then I'll use matrilineal marriages but try to make it somewhat 'realistic' (a lower class house, a younger son etc.).