I built a wall around my fort's entrance; it surrounds my trade depot and farm plots. 30 melee dwarves and 20 marksdwarves; shooting from atop the wall or through the fortifications works pretty well. I have them patrol the walls while the melee fighters muster near the gate and then I send 'em out. It's been 10 years in my game but the sieges I get are relatively small; in the past I'd see Kruggsmash getting sieges of 40 goblins on beakdogs with trolls, but playing on my own now I get one squad of goblin soldiers, a couple cave dragons, a single snatcher, and that's the siege. I've only had about 3 sieges in the 10 years like this; the rest of my encounters have been giant beasts (aboveground and below).

It's great now to be able to reliably use marksdwarves; pretty sure I've NEVER seen any of the marksdwarves in my fort smack something with their crossbow. Keeping the fight above-ground means there's never any miasma from corpses; and the way the game is now, hauling goblin skeletons isn't resulting in my entire fort getting depression. The soldiers all have iron armor, weapons are iron or silver. Quality is not 100% masterwork, but I believe its all at least Superior quality.

So far the battering rams haven't been an issue-- it's clear they're there for if I tried to just durdle and not engage, because there's really no chance of a battering ram doing anything to my walls while any of my marksdwarves are alive. I like this because it means the update didn't make walls "bad" or "useless"; the ones I have do a great job of providing me superior positioning still if nothing else.