Force Fields (though not force field modules) are immune to the Zenith Bombard ammo type. Kahuna mentioned in another thread (well, I think it was him anyway) that he will cover all his turrets with forcefields to force zombards to close, then power down the force fields to let the turrets do full damage to the zombards.
Is that a Mad Bomber as AI 1 and a Shield Ninny as AI 2, or a Mad Bomber with a Shield Ninny secondary type? The latter would be very rough.
Mad Bomber sends double-size waves and tends to use Bomber Starships. Ergo, you'll probably want to unlock turrets, mines, and MilSpec command stations more aggressively than you usually would. Fortresses will be less useful than usual, due to their penalty against polycrystal. Turrets with polycrystal bonuses will be extra-useful.
Bombers, Bomber Starships, and Plasma Siege starships will all be useful against forcefields. Raid Starships are force field immune if you need to snipe something annoying under a forcefield. If you can get them, Zenith Devastators and Siege Engines are also good. Infiltrators and Eyebots are immune to force fields.
Assuming they're available, Neinzul Enclave starships are cheap to build and fantastic force multipliers. Great for hacking, offense, defense, you name it. Just keep them out of the way, they have low health but compensate with radar dampening. Bring Mark I and II along and your hack will probably go a bit better. Flagships have radar dampening as well, which should protect them against Bombards.
Zenith bombards do very large amounts of damage, but they have a 30s reload time. Bait them with Neinzul Enclave Starship drones, fighters, or younglings (ie disposable chaff), then chase them down with something fast, like your younglings.
You probably shouldn't need to use one-shot weapons like martyrs, shieldbearers, and warheads for your first hack, or really most of your hacks.
If you're using the latest beta update, you can build 48 of each basic turret type on your homeworld, then another 48 of each on the hack world if you have supply there. If you haven't already done that, it would probably help.