Pretty much. It's not technically a 'rating' it's a magnification. A lens zoomed completely out on the camera (neutral) has a value of '1' lets say. The 0.43 would pretty much be a fraction, so 43/100 and it would be like zoomed below 1 to 0.43. So the lower you go, 0.38, would be zoomed out even further. Now the reason fisheye's and wide angles differ from eachother is the glass isn't formed with the same curvature as eachother; not universal, but the magnification is the same. So you essentially have to find a lens that you like. If there is no vignetting on the lens, then the shape of the glass will make all the difference, even when it comes to magnification because you won't be seeing everything the lens is picking up.
Does me make sense?