Certainly, these firms think that they can win. No lawyer will take a contingency case on if they don't think that they will win. But it is going to a long hard battle. People have to be ready for that. Even the Lopez case started in 2012 that is 5 years now and it is going it hasn't even gone to trial yet.
What will be sad though is if they use some of their weaker cases and use that to build up their stronger ones. By putting their clients through the emotional toll and getting their hopes up, even though they don't have a lot of faith that a win could occur. Some firms do that especially if they think that a bigger payday is waiting for them in future, stronger cases. Not saying that they will do it, but if they do it will be very sad for those clients.