[AussieRacer]

I haven't read the article, but prof you need to remember that during cornering a significant weight transfer occurs which places greater downward pressure on the tyre. That is combined with lateral forces, which will at certain levels will cause a slip angle (contact patch slipping/dragging across the surface). Maximum slip angle is achieved by a bunch of variables, including sidewall flex, tyre pressure, surface grip, rubber compound, tread depth, etc... On a car that has significant weight transfer (often can be described as a very understeery car) the outside tyre simply has too much downward pressure which distorts the contact patch (by reducing width from inside tyre to out), which reduces the slip angle and overloads the tyre very quickly. A wider tyre should maintain the contact patch longer as the sidewalls start to give way under the increased load, and hence have greater stability in the slip angle giving more grip.

Of course the same applies under braking and acceleration.

So whilst a wider tyre may have the same size contact patch by what you are saying, that shape is VERY important!