Your villains do need to have some weakness the PCs can exploit if they are to prevail in the end. Just be careful about making it something that they could stumble across accidentally less than a third of the way through the adventure.
Oh, and yeah, those are some seriously impressive glaives the guards are wielding. Or are they guisarmes? Or voulges? Or glaive-guisarmes? Or bardiches? Or guisarme-voulges? Or Bohemian ear-spoons?
In the real world of the Magicians & Munchkins universe, of course, the Oz movies don't exist. That's the premise of this entire comic, after all. But most of the other things we know and love (such as insanely elaborate pole-arms) do, albeit modified by the lack of The Wizard of Oz:
- Crystalballs is a serious documentary about high-energy particle physics.
- Judy Garland is known (barely) for doing voiceovers for poorly selling computer games, but gains widespread fame after her appearance in the first Futurama movie.
- Ray Bolger is known primarily for his dancing role in Dr Pepper ads.
- Nerdy guys make YouTube videos of themselves jumping off buildings wearing tights and capes instead of flying monkey suits.
- Without the success of The Wizard of Oz to spark interest in children's fantasy, H. R. Pufnstuf was never revived with a movie and a new series, and remains an obscure short-running TV show.
- The Cat in the Hat was never made into a film. Dr. Seuss fans never had it so good.
- The major children's fantasy background that pervades all of Western culture is Peter Pan, despite it never being much good. The original film was remade recently into a new, updated television series with a bigger budget, high-tech computerised special effects, and edgy writing. And it sucked.
- Throughout the 80s and 90s, all the greatest children's Hollywood blockbusters were big-budget boarding school dramas.
- The Comic Irregulars exist and are making a screencap comic based on 300.
Wicked Witch of the West: Well, my pretty! You may have insanely powerful magic shoes, but you're still just a little girl.
Dorothy: I kick her! 16!
Scarecrow: You don't have the reach! Her goons will impale you on their pole-arms!
Tin Man: Are they glaives? Or guisarmes?
Wicked Witch of the West: It doesn't matter! You're all going to die!
Tin Man: The armour penetration values are totally different. Realistically speaking.
Wicked Witch of the West: Armour won't save you. Your Low Empathy means I'll have no compunction in killing you slowly!
Wicked Witch of the West: And your lion friend with Combat Paralysis won't be able to save you!
Wicked Witch of the West: And Scarecrow! You may be immune to dismemberment, but you have low INT and Vulnerability to Fire!
Cowardly Lion: Gah! Throw some water on it!
Tin Man: Or maybe voulges?
Wicked Witch of the West: I'm melting...!
Tin Man: So the witch was min-maxed out the wazoo too, huh?
GM: You weren't supposed to figure that out for another three sessions...