Does rear-shock placement affect suspension characteristics?
Yeah, the main issue is the geometry that determines the arc the wheel follows as it responds to upward force on the tire.  Subtle changes in pivot points can affect that significantly.

Beyond that the spring force and damping force that the shock applies at each point in the wheel arc is obviously also important.  And differences in shock placement are one way that a manufacturer would "tune" this.

There is also, of course, the physical stiffness and durability of the shock mounting scheme, and the simple fact that some schemes facilitate a good frame design better than others.  And of course "coolness" and novelty of appearance are major criteria for the frame builder.

One critical factor that isn't visible in those photos is the precise location of the pivot at the front of the chain stays.  That probably affects "bob" more than any other factor.