The Difference Between Ryder and Ryder

I said something in another thread about Ryder dancing basically along the lines of:

"I hope the Ryder siblings have varying degrees of skill, so that one is really good at dancing and one is really bad at it."

After I thought about this statement for awhile, I actually found that I wanted that to be true in more aspects than just dancing. I think it would be really cool if the Ryder siblings had different sets of skills that would be implemented in different ways into the side stories (or even the main story). Now, normally, since both of these characters exist at the same time, I wouldn't feel the need to even bring this up, but since both Ryders can potentially be the protagonist, that would imply that they are interchangeable. 

While this makes the most sense from a gameplay perspective, having the same base stats, being able to use the same classes, etc., I think from a story and character perspective it would be far more interesting if they weren't just interchangeable between one another. Ideally in a way that wouldn't affect the gameplay and make the player feel like they had to pick one character for certain in-game advantages.

Like, for example, the dancing thing. Maybe Sara is a great dancer, but Scott has the ol' Shepard Shuffle. Maybe Scott, alternatively, is a good cook, which could be expressed aboard the Tempest, while Sara's attempts result in misery for everyone involved. Maybe Sara was better in school than Scott, and as a result, is seen as the smarter of the two. Maybe one of the siblings is considered the favorite in the eyes of PapaRyder. 

Or, for main story examples, perhaps Sara could have insight on certain pieces of tech that Scott would lack due to her backstory, while Scott would be more militarily inclined, having more of a "boots on the ground" way of thinking. This wouldn't affect the dialogue options available to the player either way, but would add some "flavor" to the protagonists that separate them from one another.

Maybe Bioware is already planning things like this, maybe not, but since the main character isn't always their own character, but one of two siblings (unlike Hawke), I think it's important to differentiate themselves. What do you think, BSN? Would you prefer they be interchangeable so that you don't risk missing out on any kind of unique dialogue by playing as a certain character, or would you like to see them be more independent as characters?

If so, what other examples do you think could serve to differentiate the two? Discuss.