I doubt the person writing the text for the Volt Driver had an idea of how much one terawatt is, let alone dozens shot around as a handheld weapon

I just read Kanden's scan and-

A disruptive electromagnetic field appears to surround the hunter KANDEN, analysis suggests voltage potential comparable to that found in lightning storms. KANDEN carries the Volt Driver, which is capable of a charged blast that can disrupt the COMBAT VISOR.

It's actually really consistent with the terrawatt statement. A single lightning bolt is said to be billions of watts, and that's just passive on Kanden at all times. It appears they looked it into enough to know what they were saying.