Dude the empire was using Crossbows, and they knew how to make them.
Crossbows weren't in Skyrim originally because the devs didn't want to put them in.
I think it was originally because of physics and collision issues (Specifically in Oblivion). When Fallout 3 came out, it had the Railway Rifle, and that gun alone had a lot of game-breaking bugs (Lockups and the like) so at least that makes sense.
In Skyrim, I think they're just afraid of any redundancy at all, which is kind of stupid. I've said it once, and I'll say it again, Bethesda is so afraid of redundancy, if they ran a Nuclear Power Plant, we'd all be dead.
But at least we have Crossbows now, that's one off the list (Of weapons alone)... Maybe Spears in Hearthfire?