As a general military practice, it is a good idea to have redundancies in a system so that the destabilizing of one of the hyperspace generators would not result in total destruction of the death star.
Note: This information is taken from Star Wars Legends, as that is the only place that actually delves into the physics of hyperspace jumps and hyperspace generators. As of yet there are no cannon source I know of that delve into the subject deep enough to answer this question.
However, if one destabilized the entire matrix, or did something to enough of the generators the Death Star would be pulled apart into many pieces. The Physics behind hyperspace jumps appears to not only be complicated, but also very stressful on the objects involved. Hyperdrives had many safety mechanisms preventing them from failing (1), but they could still be sabotaged. Wookieepedia lists two specific components, a "4-axial stabilizer and hyperdrive regulator", meant to specifically prevent the ship from being torn apart by the physics involved in a jump. One can assume that sabotaging these components would cause the physics of a jump to then tear a ship apart.
Additionally, hyperspace generators work by generating fields. If one were to sabotage the matrix so badly as to guide each of the hyperdrive generators to jump in different directions they would tear the death star into 123 parts, one part for each different hyperdrive field.
(1) Wookieepedia, "Hyperdrive" http://starwars.wikia.com/wiki/Hyperdrive/Legends