Breloom, Breloom, Breloom
Even though you have Combusken, still get Breloom. You get it as a Shroomish very early in the game, plus with Mach Punch and it's amazing Attack stat, you're bound to destroy Wattson, Norman, Archie and Sydney with it.
The moves I would recommend for Breloom is Mach Punch, Poisonpowder, Sky Uppercut, and your choice of move.
Hope I helped!