Earlier quoted context omitted.
why would they sue their client ?! what does that say to all their other clients ?
Clients sue other business partners all the time, that doesn't mean they stop working together. There's lots of examples of this.
Is it a 1:10 ration, 1:1000, 1:100000?
You just don't know because companies don't tell you this information. If for example there were a magic oracle that forced every suitable action into a suit, would the entire legal system of the US instantly explode?