When would YOU run a fighting move on LandoT?
For what purpose would YOU decide "Hmm, I think this fighting move would go well on my Ground/Flying type"
This isn't about surprise, it's about practicality. Who are you trying to surprise with a fighting move on Lando?
I saw someone run Trick Ring Target Victini + Poisonium Z Growth Venusaur specifically to muscle past Heatran which is usually a hard wall to Chlorosaur, that's a surprise.
What would Hammer Arm/Superpower Landorus hit?