what are your thoughts on Ruby's "it's always been just me, but bigger" line?
That is something I’ve been thinking about. Because in practice we can see that the three Rubies are not identical; palm-Ruby seems a little exasperated by the other two’s punch-happy enthusiasm, and of the other two, one seems to focus more on the idea of fighting while the other seems to focus more on the idea of dominance via fighting. Their vernacular is similar, but that’s to be expected- they’ve been raised in similar formats.
The Mega-Ruby can’t have the same personality as each individual Ruby because those personalities are not the same. But her components have been trained to think of, and present themselves, as interchangeable, uniform, all the same- so she doesn’t analyze herself. Especially if she’s only formed for fighting and not allowed to hang around or throw herself through especially complex psychological self-analysis, her component Rubies are not going to find out that what’s comfortable to one of them is not to the others.
But Ruby and Sapphire? Different contexts, different backgrounds. Sapphire has been encouraged much more to assert her individuality, because she’s rare- there are not a lot of other Sapphires around and she’s used to being “the Sapphire” rather than “a Sapphire.” A resource as valuable as future sight would probably be stretched quite thin- it doesn’t make sense to gather them all together when only one would suffice.
So when Ruby and Sapphire come together- they, and Garnet, are immediately aware of their difference. It’s expanded, highlighted, and, once Garnet moves into the context of the Crystal Gems, nourished and encouraged. Garnet explores how she is and is not like her components, develops a conclusive theory of who she is. She’s allowed to think about herself in ways the Mega-Ruby hasn’t.
Mega-Ruby hasn’t really thought about how she’s her own person, because she views herself as just stacking together of interchangeable, identical individuals. So I feel like Mega-Ruby really could’ve been much more of her own person if her components were allowed to develop and explore their individual identity outside of their shared thread of all being Rubies. But since she hasn’t, she, and her components, see her as just an extrapolation of each of their individual experiences, which they assume are all the same.