"...Hmm. It depends on the construction - the works put out a 'build your own' kit, for an army on a budget, which is maybe thirty in metal parts, but you'd need to have some sort of ability to rapidly hew and assemble wooden parts - or some equivalent - in the field, because I imagine that minor creation's right out for supporting infrastructure...there's the collapsible tripod, which is about half that, overestimating, and isn't necessarily battle-tested, it's mostly used by surveyors, though one of them wrote in to say it made a decent bludgeon in a pinch...I think that one was from Ustalav. Anyway. I think a mostly metallized ballista...
"Oh, hmm, you could base the tripod off of the same spell, come to think of it...ah, wait, no, it vanishes after a round...
"Anyway.
"You'd want to split the parts up a bit, probably, but you could add it to a two-man or three-man team and they could crank off a shot a round, or more, with training, especially if you had the budget for good support equipment - throwing what's effectively a spear with much more strength, distance, and accuracy than any man. Maintenance might be a pain point, though. With the - preferring it to be magicless, and possibly less overall understanding of metals and care requirements thereof? I'm - imagining that the name 'Steel Exiles' has a meaning, because unfortunately if someone told me one way or the other it has completely gotten lost in my head somewhere."