Perhaps, but you also have to keep in mind that there are massive sections of the Old Testament which do not even really directly concern religious dogma. The Old Testament is rougly only half legitimate religious document, with the other half being devoted to a highly generous and even blatantly propagandistic retelling of the self-written history of the Jewish people.
It is sort of to be expected that many of these sections detail Jews "kicking ass and taking names" in a fashion which ancient readers would have found to be enthralling. It is also to be expected that what ancient audiences would find enthralling is going to sound rather brutal and cold hearted to modern ears.
However, even then, it is worth noting that the Old Testament Bible shows many of its greatest acts of vengence being accomplished by God himself (i.e. the ten plagues, Sodom and Gomorrah, etca), rather than human beings. It also maintains a fairly consistent moral code throughout.
The Kings and people of Israel are repeatedly punished for the immoral actions (murder, theft, adultery, ecta) they commit. The Koran, by way of contrast, seems to give Muhammed almost universal moral license with regard to his personal actions.
