I'm doing this with Silentthunders, however I find as soon as Necromancers show up you need at least some cage traps to find the stealthed ones if you have a lot of ground to cover. Which I just so happen to have. So basically no traps until the zombies start approaching, which is a shame considering how the goblins are few and far between. And I just don't like atomsmashers. The quarry also has a spiral rampway which'll be connected from the surface to the caverns once I breach it (I just can't seem to find the damn things) so all the zombie trolls and FB's can play with my Dwarves up top too.
Defense wise, the outer wall is too large to have any large guard so I have to send a squad of marksdwarves or two around the walls to kill wandering zombie ravens. Oh and the outer wall is also being reinforced with constructed walls to thwart any attempts of possible future diggers making it inside. And on the off chance that they do make it inside, the wall will be flooded with water. The water'll freeze killing the digger and replacing the broken segment of the wall. Ice ice baby.
AAaaaand it is an above ground fort, so everything used to have a completely uncontested access to the central hive from all directions, but now there's only 3 entrances I know of, West (main caravan entrance), East (small postern) and the sky (which happens to be 100 zlvls high).