Removed this example. I expect the objection is correct. Perhaps the definition needs to be clarified.
Mythbusters featured a "hwacha" or multiple arrow launcher. Employed in large numbers, they could have been very lethal.
The Hwacha was NOT a siege engine. It was a battlefield anti-personnel weapon similar to pointing a cannon at ninety degrees and filling it with buckshot, then firing it. The arrows would have had NO effect on buildings, and as such the Hwacha is not classified as a siege engine.
Removed this example. I expect the objection is correct. Perhaps the definition needs to be clarified.