I believe you are correct re: Fairy Active vs. Cascade w/Dawn...
In a similar way, Fairy Liquid does correspond to our Dawn, in terms of product placement....if I am not mistaken, it is still the leading dish liquid in the States, followed by Palmolive.
I'm sure the actual products differ chemically, as different countries have differing water conditions and cleaning needs.
Ecover products run the gamut here, but are now easier to find then before. I like their limescale remover (mind you, I have soft water), and their floor soap beats our Murphy's Oil Soap by a mile....again, their products tend to be more expensive here.