There is a simple answer to this. The AI in GW has a huge advantage. I don't know how anyone that has spent extensive time playing can't see this. The AI opponent almost always has everything go perfect for itself.
Toons that you could normally kill with a certain series of moves are almost always left with that sliver of red so that you either have to waste one more turn to finish them off, or they get healed, or get one last shot in on you. If you really pay attention you will see that it often doesn't matter if you switch a higher damage char to be the assist. You will either do the exact same amount of damage as before or you will suddenly get dodged.
You almost never get a big critical hit when you need it to finish off an enemy char. The AI crits at a very high rate. The AI dodges at a very high rate. A squad that I would absolutely wipe the floor with in arena and walk out with all my toons at nearly full health can somehow manage to give me fits in GW, kill my toons, and so on.
I could almost predict to you what will happen on almost every move in GW. Sid is almost dead and his turn meter is almost full, your next toon up is a Jedi, don't plan on hitting him about 90% of the time. Some other toon is almost dead and all you need is a critical hit to take them down, nope, not happening. Your own toon is below half health, your healer is up next and the AI needs a critical hit to take them down, count on it!
For those of you that don't believe this, try something... Bring in a mirror image of the AI squad, mimic their moves. That should make it a really close match right? Even if your squad is more stars, level, gear, etc... You will notice that the AI squad somehow can take your chars down faster. They get some nice crits, you don't, they get some dodges, you don't. It's uncanny.
Bent Wookie can bring out Pikachu if he wants to. Nobody will ever convince me that GW isn't formatted to give the AI an edge.
