I think my Mary Sue meter just exploded.
Please join these multinational petitions against ACTA. Sign up now. Every voice counts.Why? They don't retain any more clan affinity disciplines than any other power, it's just that they trade out having the exact same powers as their root clan for a pair of disciplines that are a lot more fitting - hell, the Macellarius clan are *also* known as "Gluttons", and that's primarily because of their Gustus discipline.
It's mostly the two signature disciplines.
Please join these multinational petitions against ACTA. Sign up now. Every voice counts.The whole point of signature Disciplines is that they are only availiable for the Bloodline in question. I. e. not a Burakumin? No Getsumei for you. Ever.
Please join these multinational petitions against ACTA. Sign up now. Every voice counts.If this is going to be your character, and the GM lets you get away with it, why not?
If this is your game, I'd rather just drop the complicated backstory and make those disciplines that you like the default for a clan or bloodline.
Generally any sort of munchkinning where you break rule limitations should be discouraged I think. The "splats can never overlap" rule applies to bloodlines just as well. For example, you could make up a completely fine story about a werewolf replacing all his blood with a vampire's and gain some of their powers as a result. You could even balance it properly so that the character isn't broken. But once you do something like that you encourage everyone else to resort to similar tricks to be able to ignore the limitations they don't like. That is my (un)educated opinion.

This idea for an element to add to a Vampire The Requiem game to mind recently, but I'm not sure if it's legit, so I decided to drop by here to see if it could work.
The core of the idea is a "dynasty" (unbroken line of sire, childer, grandchilder, etc) of Nelapsi, descended from one important family patriarch/matriarch. The individual in question once went on a pilgramage to Italy, where he found himself getting on the wrong side of an isolated household of Macellarius vampires. They treated him to one of their sumptuous feasts, and then threw him to the horrifically bloated patriarch of their household; whilst this elder Macellarius was stronger and more potent than the Nelapsi, its massive corpulence made it sluggish and slow. T Husly, Glutton battled Glutton, and it was the Nelapsi who sank his fangs into the swollen abomination's neck and drank deep, diablerizing it. And then, flushed with potent vitae, he attacked and consumed the other three Macellarius vampires of the household, diablerizing them as well. Through this, he came to "inherit" their bloodline discipline of Gustus.
The other notable event he had before settling back to isolation was... "acquiring"... the discipline of Continence from a Formosae. Realising just how useful (and fitting) these two disciplines were for the "true" Gluttons, he has since made sure to pass them on to his childer, and their childer, and so on. As a result, the modern-day childer of this dynasty have lost their parent clan's affinity for the mental disciplines and instead have an affinity for the two disciplines most relating to their monstrous appetites.
As a result, this "bloodline within a bloodline", whilst functionally identical to the Nelapsi from the sourcebook and still able to learn their bloodline-unique devotions, modifies their Bloodline Disciplines to be Celerity, Continence, Gustus and Vigor.