If I were to guess how this would play out. Reverse Flash would kill Black Widow and Hawkeye instantly. So that means 4 against 6. Atom Smasher fights Hulk (Hulk wins), while Thor fights Weather Wizard (Thor wins), Mist fights Iron Man. Multiplex, Cpt Cold, and Reverse Flash defeat Cap quickly. That means 3 against 6. Then Hulk and Thor would win. 3 against 4. Reverse Flash defeats Hulk by vibrating through his head or chest. 2 against 4.
Iron Man and Thor are in the air against Multiplex, Cpt Cold, Reverse Flash, and The Mist.
Iron Man would have to defeat the Mist in order for his team have a shot. If he does he could also potentially take out Multiplex and or Capt Cold.
The Real problem is reverse flash, he is on the ground while Thor and Iron Man may be in the air. If they have to fight to the death, then advantage Reverse Flash because they would have to get close to hit him.
CW villains win- mainly cause of Reverse Flash.