Additional necromancer question, would a stream be more of an asset or liability against necromancer sieges?
I know from adventuring experience that undead can swim just fine even if they spam *flounders around in the water*, but I guess it depends on how you use the stream?
There are..... reasons why you don't want a stream, although it DOES help.
I embarked on a river with two towers in range. Here's what happened.
1. Bolts sent undead corpses dodging into the river.
2. They stayed there forever, creating a scenario where they caused work stoppages and my fort to be permanently under siege.
Zeds can climb out from a river/pond channel, but don't make the mistake I did by assuming that they would do so. Also, they seem to prefer bridges to path through, so, a bridge can be a deathtrap for them when covered with marksdwarves, but see above.
Don't assume that rivers= impassable though. They can and will pass through it if there's no other way in.
Also, the dwarf corpses that they reanimate WILL litter up your graveyard if you set it to burial citizens. I sorta enjoyed that, gave me a thematic reason to embark against the undead afterall. I have no idea what that will do for your FPS though.
Siege= FPS killer.
Also, Undead vs Goblin can be very fun to watch. Refer above bridge for scenario. The goblins dodged into the river and didn't reanimate. Don't ask me why.
Necromancers create campfires in siege.
A more aggressive attack against necromancers is impossible without walls channeling them. Their ability to dodge your patrols is superior to your ability to sense them. They WILL leave the map eventually..... its just that you might never know when they do or if another ambush just emerges along. I had the scenario once where my fort was under ambush from the enemy for two years, before it became a goblin siege and well, above scenario happened.
Simply put, if you play turtle, your refuse pile is safe from necromancers and the turtling design works against both sieges and goblins. Just.... be careful about caravan access as a necromancer once animated a hand while inside my trading lanes.
Melee dwarves= no. I love melee fighting. But against the undead, its impossible. Here's a fun fact. After a hand/skeleton has been mauled enough, they have missing parts. If your dwarf hit them in said missing part, its a miss and does no damage. But said hand, despite not having any fingers and etc, despite massing so little that your combined dwarven army can't hit it 6 times in a role, can do enough damage to fracture your dwarven plate coated fighter into submission and then death.
So, an ideal defence design is to have an island with moats, a bridge where your marksdwarves can hit them. A simple channeling should work and if you do the standard two tile wide moat, you should be able to be safe from dwarves dodging in(no need for water in this case).
What I did was to create a skybridge, allowing my dwarves to fire upon incoming intruders at will.........
Kinda worked until that dastardly elite goblin crossbow lord came knocking........