I'm kinda leaning towards that, except I'm sure I made a mistake in saying "the" word, when it's "a" word. There's certainly more to it. It's just a thought experiment, right now, but might turn out useful.
For example, Gnome or Goblin Sorcerers are incredibly streamlined - grab one of the 3 class features and run mad with it. They're certainly powerful, but not in a way that's exactly "optimal". A human or a dwarf sorcerer are way more open-ended as they get something out of their other class features, and use the fact that the mana pool get them levels to turn into melee monsters later on - since this opens you up to leveraging more stuff, which means you get more solutions to more problems, they kinda look more like what I'd describe as "optimal".
Halfling Bloodmages are more streamlined, Gnome Bloodmages are more optimal. Maybe.
Been thinking about "hybrid" too, it's also a bit of an umbrella term that has always kinda confused me. There's guys who use both bars well enough simultaneously and then there's guys who just transition really well. Elven Priests, for example - the Priest is so streamlined that it's hard to think of him as Priest rather than a Warrior. Halfling Priests are something like the most streamlined thing there is. But add Elf to priest, and what you get is something which plays like a great transition hybrid any way you take it.