I think I'm going to be able to do it all without touching the original scripts now, actually, but thanks! There's an easy way around reworking the random drop functions...just dynamically remove everything they could possibly add from the inventory of each enemy once it's perceived, then fill them up with your own stuff. Works perfectly thus far.
In other news, I just spent freaking hours wondering why the hell my AssignCommand() blocks weren't working right, or at all, with my SetCommandable() calls. I wish I'd known earlier that these commands are run at the end of the current script and accordingly you have to go about them a little bit backwards. This scripting system can be awfully peculiar at times.
edit: and yeah, this mod's for K1 right now, but once I'm done I plan on porting it to K2.