Originally posted by Nerevar:

i mean the cannons are meant to fokus on actual THREADS. do you really want your bolts go to waste on GREYDWARFS? i just told my cannons to fokus seekers which can actually reach my base no matter what. most enemies cannot even reach it so why gun em down? waste of ammo.

choose them to fire at things you view as a danger to your base. brainlessly fireing at everything is useless.

and by doing the above you also dont get shot by your own cannons anymore.

and it gives trophys some usefulness i guess. better than nothing. and still requires player to think of what to do instead of beeing braindead.

yes. I am probably going to have 1 for boar and 1 for rock throwing dwarves. The dwarves are able to chuck rocks at my stuff while swimming, and are slowly damaging stuff with it from farther out that I can block easily. I have rigged up a ballista just to cover the waterfront where they keep swimming. The boar because sausage is still useful around the house during raids or chopping trees etc.
But I will probably leave them on all targets. They both can hit fuling nightspawns and that resupplies their ammo. I don't go out in front of them; I put them in places I don't need to go.

at the end of the day, the ballista's usefulness is 95% deterrent and 5% free loot.
their arc (current live implementation) is avoided by all mobs. I can make that work for me.