One problem is that "sharpness" is not a well defined term, it's actually a combination of several effects, and in fact involves more than just the lens. First of all, a lens with high contrast will look "sharper" than one with low contrast, even if it has the same resolution. This is why you cannot just look at numbers, there is no way to say what lens is sharpest without looking at sample photos, or preferably by using it yourself in real life shooting conditions. Then there's also the fact that motion blur is lessened with faster lens, which will also increase the sharpness.
Finally, with digital cameras, the strength of the anti-aliasing filter comes into play. Unprocessed, photos taken with a camera that has stronger anti-aliasing filter will look softer, even with the same lens. And then you can start talking about ISO. Images taken at high ISO will look less sharp than at low ISO, even if you don't blur the image to get rid of noise since you will lose contrast. Again, resolution numbers will not tell you this.
That being said, modern lenses are all pretty much sharp under ideal conditions, so using a kit lens for amateur landscapes shouldn't be a problem, at least in that regard.
The reason you aren't getting the discussion you want is because it is a pointless debate. Resolution just isn't an issue nowadays, and if you are just going to compare the numbers between your equipment, you're probably better off going Canon; they have more megapixels.
