Before I take a look at the team, I should clarify a thing about Foul Play. It takes the opponent's Attack stat and modifiers into account, but the rest is applied as normal. This means that burning the opposing pokemon will not decrease the damage dealt. However, being burnt yourself will. Similarly, if you hold a life orb and use Foul Play, you will increase damage by X1.3 and lose that 10% of health. If it's them who hold the life orb, it will not matter at all, and you will see that no 10% damage has been reduced. You can try this to verify.
Here's how Bulbapedia words it
About the team, Tomas suggested some changes that effectively have 4/6 of your pokemon thrown out. I would too suggest Knock Off instead of Double-Edge and Darmanitan instead of Arcanine. There's no reason to use the canine if you don't do the Intimidate set. Darmanitan, especially with a choice scarf, is a much better option with pivoting potential. Unless you wish to turn Arcanine into a more physically defensive pokemon with Intimidate, I recommend Darmanitan.
Also, give Sableye a 248HP,252+SpD, 8Def Ev spread for maximum longevity. Few Fire type physical sweepers exist in the UU meta, and they are the only ones immune to your prankster WoW. Your 248HP EVs are more than enough to outlive them after a successful WoW. Plus priority in recovery is always nice. You could even go for Night Shade if you feel like it, but there are still some Normal types lurking in lower tiers.
I know Swalot is a pokemon you like, but it's not that effective. It's slow, weak, and outclassed both in the offensive and the defensive by better pokemon. Plus, it's Ground weak, and you cannot rely on Aerodactyl to avoid all Ground attacks or Leafeon, since it's actually quite frail and has no recovery. An awesome alternative to Swalot is Amoonguss. I usually don't like having 2 Grass types in my team, but if I were to choose which one to drop, it would not be Amoonguss. Spore, Sludge Bomb, Giga Drain and a filler move of your choice (between Hp-ice, Hp-fire, Synthesis and Leech Seed) make this pokemon one of the most deadly even if it's just a stally mushroom, usually seen in a Regen core. It can fill in many teams, check the fairies, survive physical and special hits alike, mainly covering Sableye where it cannot work properly, and as for Fire types, you have your Fire pokemon of Choice, Aerodactyl and even M-Amphabulous to take care of them.
So there you go. I suppose, without changing your team too much (only 2 poke-switches and I kept Leafeon) we can make it better and keep the roles.
Get some set ideas from smogon as well, and come back to tell us about your progress. A replay or two would help (mainly because we are too lazy to read at long logs but all die for some video action)