Pretty much, Lorel, yes. To add further, I don't think those three = aiki. I think those three are parts that help make up aiki, but not the only ones.
And let me make the disclaimer that I'm going by what I know now ...
as a beginner ...
It could be that what Shioda meant by chuushin ryoku, kokyu ryoku, and shuchu ryoku included opposing sides, spirals, etc. Hard to tell with the way the books and interviews are written.