It is a good explanation, but consider this:
Given a perfect environment (where friction plays no role) moving "Block A" will require the same ammount of energy to overcome inertia as moving "Block B". However friction plays a major role in tire function so this is obviously not the case. Assuming both blocks are made of identical materials (with the grain and orientation of the material being equal on all faces, regardless of orientation), and assuming that the friction/area is uniform "Block A" will require a greater input of force to move than "Block B" because one needs to overcome both inertia and total contact friction.
I feel that perhaps this discussion is becoming mislead by the belief that a wider tires automatically = greater contact area. Due to a tire's structure it is infact the tire pressure that determines the size of the contact area (which in turn provides friction, which in turn provides the grip exhibited by the tire). The main advantage of using wider tires is that you do not need as much air pressure to ensure that the tire maintains its shape (due to the spreading of load across a larger surface area). This reduced pressure allows you to provide a greater contact patch to the road surface and also reduces the rate at which the tire heats up (because lower pressure = less air molecules = less molecular friction = less heat).
The problem with wide tires comes when the road surface gets wet. Because water is a liquid and liquids, like solids, cannot be compressed, the width of the tire may trap water under the larger contact patch thereby preventing its contact with the road surface. This is what makes aquaplaning so dangerous, since the tire is effectively trying to "grip" the water and finds virtually no friction thereby robbing the driver of control. Wider tires are at far greater risk of this phenomenon because of the larger contact area they have with the road, and is the main reason that there is such a large difference between "wet" tires and "dry slicks" in racing. Wet tires allow water to be channelled away from the contact patch and allow the remaining rubber to grip the surface of the road safely. However, using wet tires (with their channels) on a dry road provides
less grip than a slick tire because some of the rubber surface area is absent due to the channels.
Essentially, the upshot of this whole discussion will end up being that there is no such thing as the perfect tire. Tire performance, usefulness and safety is determined by a large number of influencing factors including the road surface, the weather, the vehicles geometry and suspension as well as the tire compound and the contained pressure.
A pretty complicated topic, I think we can all agree!