I'm pretty sure that ranged would be the best choice seeing as two of them are weak to it. You should also use something that isn't hydrid armor, barrows armor perhaps.
Airuts, Kal'gerions, Glacors, Automatons, Legios, and Ganodermics are all poison immune. So really the only things that they would be good for would be Tormented Demons, Eddimus, Celestial Dragons, and Nihils. Everything else isn't worth killing or dies too fast anyway.
You might be able to set up your cannon and then get out of combat by safespotting or something. That should allow you to attack a bunch of them at once, and a royal cannon would help a lot with that. I'd really just recommend killing them in the CT making sure to use Chain and Dragon Breath constantly.
I don't know whether it applies to monsters or just PvP. That would be something that you have to test on your own. I mean, every monster in the game outside the wild acts as if it was in a multi-combat area, but I don't know it that still applies to them in the wilderness.
It would technically be best to use weapon poison on anything that isn't immune to poison, but the fact that much of the stuff that isn't immune gets 2-4 hit anyway meaning that it usually won't even do poison damage before they die. QBD is immune to poison (just look on the wiki to see what is/isn't immune). The best use for weapon poison by far is PvP.
I'm mainly curious but as this is somewhat relevant to the topic at hand: does smite disable the fury shark protection effect or no? Smite drains prayer points. Fury Sharks aren't prayer points.
I've been on a field trip where I walked down the road like 5 minutes to a small park owned by the school to do insect sampling, but that's still school property..... Never been off of school grounds for a field trip.