You have so very many artifacts Dunamisdeos! Do you play 1 main fort?
I specifically like to abandon forts and start new ones in more !FUN!, dangerous and goblin-infested areas if I don't get enough assailants :p.
It sucks when a fort suffers because of inaccessible stuff in the surroundings, or when siegers run out.
I straight up just abandon the site and leave, because frankly, I love watching my tiny armoured dwarves march to war against goblin hordes.
A good way to guarantee sieges is to have dead dwarf-civ and a world full o' goblins
(makes the dwarf fighting seem like desperate revenge too!
"You extincted my race but we'll survive and fight you off! I. AM. DWARF! *berserker rage*"
"You killed my ancestors, now I'll return the favour! *uses siege weapons*"
"My ancestors are dead, but not the spirit of my civilisation!" etc.)
If you kept wiping out sieges and embarking near goblins, you could probably wipe out most of the goblins in the world through fort mode!
Might make a good challenge run if you like sieges (which are quite easy anyway):
1. Dead civ, world infested with goblins (10 000 goblins in a medium-sized world, anyone?)
2. Embark near them and kill all the siegers till the source is depleted.
3. Abandon and move on to another area and do the same until only a few goblins live in those sites too. Migrants will be your highly skilled warriors from previous battles.
4. Eventually deplete all goblin sites to a handful of wimps.
5. Then take an adventurer and finish them return the favour put a messy end to extinct Goblin kind in retaliation for your destroyed civ.
For revenge and justice. For your ancestors. For your civilisation. *looks at symbol of dwarven civilisation and government and salutes it*