In the Welsh tradition, prior to the English Conquest, and here we're basically talking the Medieval Saint Years from the end of the Roman Period through to the last Welsh War against the Plantagenet King Edward the First, also known as the Hammer of the Scots, it was around the end of the Thirteenth Century, Welsh names were primarily nicknames and no one really had what you and I might think of as a surname. But because it was important to know a line of ancestry and avoid accidentally committing Lot's sin, a person's name would include the person's father, grandfather and back into the past. This meant you'd get something like Timmy ap George ap Henry ap Edward etc., of course the names would be Welsh names not English names. After the English Conquest all the true born Brave Welsh Princes, or landowners, had been executed, the less brave had married the right person, they went all English Corporate if you like, and if they were very good, denied their past adopted new ways of describing themselves as loyal to the English Crown they were allowed to keep a little something. The common people were less prone to such abject behavior, no matter who ruled their lot, nothing really changed and some of them didn't hold much for the idea of surnames, until slowly, following tighter and tighter control by a Central Bureaucracy the Surname became inevitable as the Parish became less and less influential. But even today the Welsh people actually have relatively few Surnames, and round the world there are probably less than 20 million people with Welsh Surnames.
You can say what you like about what might be called Rationalization, a set of standards to which all will agree or be forced to agree. Consider Centigrade, Liters, Quarts, Pounds, Shillings and Pence, Miles and Kilometers. Worth also considering something like a Kroger's Grocery Store, no matter where you might travel up and down Kroger Territory you can go into a Kroger Grocery Store and know exactly which of the two or three hundred aisles the seventy odd different kinds of Milk can be found. Then there's things like MacDonald's, a plague that stretches from Coast to Coast, Brand name Hotels are the same, and you can travel for miles and miles without ever having to see anything or come into contact with anything strange, or different, or even remotely exciting. Nor do cell phones do much for moral fiber, they serve merely to increase blandness and persuade the dreamers to include in their fantasies the colonization of somewhere like Mars, or obsess on Decorative Accents to impress the neighbors. Either way in more recent years, and here we're basically talking forty or fifty years ago, there was a resurgence of interest amongst some Welsh people in more traditional ways of being. And this included names. All the same, if a person went for his job interview for something like a postal worker and announced that his name was something like Llewellyn ap Gruffudd, odds were he'd be treated with a degree of suspicion. Only the bolder, more passionate, adventurous people would try it and many of them had no work. For my part I'm so well adjusted I'm about as adventurous as a Poached Egg.