if youve read WWZ,youll see how tanks are essentially useless along with conventional arms,antipersonnel(mainly shrapnel based) explosives wont do much against a horde of zed,all but the very closest zeds will be unharmed,shielded from the blast by the hundreds of other zeds,all packed together nearly shoulder to shoulder.you can run em down,may not kill,but will incapacitate any that go under the treads.but then ya gotta worry about fuel and hope the treads dont get gummed up with dedzed.