Won't work, because it's PC Doom based while Doom64's monsters follow a different scale and proportions. Scaling it up won't help, since the proportions will still be off, and stylistically it still isn't a great fit - not to mention the cleanup you'd have to do after scaling, which sounds like a lot of work for a pretty meagre result. You'd have more luck editing the Doom64 soldier sprites to incorporate the chaingun, ammo pack and adding some more muscle to the body.
Best bet IMO for bringing in any missing Doom64 monsters, is to do some proper high poly models matched in style and color, and just render them out. That pretty much means doing some proper custom content - I've been meaning to try, but one epic (Supplice) is already enough on my plate.
I'm surprised, but it seems no one thought of this - If I was to try to rip/repurpose something, I'd give a try using Doom 3's Archville and Revenant (With that transparent skin thing removed). I think they could be a decent fit visually, plus they're already animated. I wouldn't go for 2016 though.
Spider Mastermind would have to be created, however he could be very similar to Doom64 Arachnotron so that's a very solid reference point to try to match up.
That's all from me, now let's keep Supplice in the Supplice thread, and Doom 64: Retribution in the Doom 64: Retribution thread.