I may be out of date (2004/5) and will look further into it.
Presumably if the limitation has been set at 50 then there will be a load of other law firms filing the same for every 50. The lead case gets heard and depending on the outcome all the others are decided too.
I understand that the lawyers have been allowed an uplift in their percentage. From 30% to 40% perhaps they argue with smaller numbers of the class they need a bigger % .