If you also read the Zombie Survival Guide prior to reading World War Z, you get a much, much better idea of how the virus that animates zombies (Solanum) affects their physiology so it is much more believable that certain things that would affect humans would not do the same to zombies. Particularly where it describes what happens to the brain during infection.
Yeah, I read both, twice. It makes the brain mushy, and he gives a lot of lip service to that "black goo thing" that the zombie body has, but as I pointed out: Liquids actually intensify the effects of explosions.
Something explodes in water it will hurt you more than if you were a comparable distance on dry land. Not to mention that zombies could not walk on the bottom of the ocean and come out unharmed. Also, ice damage affects every liquid. The only way to stop ice damage on cells is to stop them from freezing (or freezing them absurdly quickly) which happens in none of it. Those two things get a hand-wave so I'm willing to let that slide I suppose, but it's pretty weak.
So bombs would still be a lot more effective than the books make them out to be. Now I agree fragmentation explosives are next to pointless because they're meant to propel shrapnel. However, the stuff dropped from planes usually doesn't concern itself with that. HE tank rounds would have been pretty useful (more than canister actually).
Also, Brooks apparently thinks we're still fielding the first-model M16 from 'Nam. Stuff that was fix during 'Nam, by the way. The M16 and AK-47 are both better than ever, and for zombie killing they now both take the standard NATO round because Russia is a good guy now.
Also, the 5.56 Nato is probably the better zombie killer. It's comparable to a .22 in weight and effectiveness.
Now, don't get me wrong. I love the books (remember I read them twice) they're a stealthy and subtle satire, but I just think he tends to fudge more than you'd expect to prove his point. *shrugs*