Blue is probably closer to Red than Scorpion is to Sub-Zero, if only because while Red's got some issues with contests (is he Red? is he Ash? is he just the Pokemon Trainer from Brawl? why should I care about him?), Blue's fanbase is more 'solidified'. Everyone knows that Blue=the rival=Gary Oak, and the easily recognizable design helps with that.
Anyway, there's definitely something more to Ryu/Ken like you said, which is why it's one of the most iconic gaming rivalries. I'm just saying that among people who played and loved RBY while growing up, Red/Blue was about as memorable as it got.
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Black Turtle did a pretty good job.