If I were wearing cloth based armor, and drenched in oil while near a roaring fire, I'm not sure my biggest concern would be on my footing.
So, look at your character sheet; skills, stunts, aspects. Tell me how you can move a bucket of oil from one place to another, and what it might entail. For the record, I have at least one idea, but it's not my character.
For mounted combat, you have choices to make. Technically, a spear gives the footman a distance edge. However, these guys don't have a solid formation, and most don't have a lot of experience fighting a horseback rider, either. Your horses could probably run over any of them, and you're all skilled enough riders to close and negate the spear's length advantage.