several means 1-100(maybe it's wrong), everybody know
class BaseClient {}
class Client1:public BaseClient{}
class Client2:public BaseClient{}
class Client3:public BaseClient{}
...

void foo(BaseClient& b){}
maybe it defined in another class, you don't need modify it if you add a new client only

but, I hope to get a better way to implement it,

Actualy, I don't understand your story about name, what do you really want to do?