I guess not 

. 
Originally the Skaven army was designed with the rule that they could not advance after destroying an enemy - only if they destroyed him in the first round of combat. 
Later on someone decided to leave that rule away obviously not being aware that there is a "rat-tail" of other things linked with that rule. That's probably the army list you got to know. 
Leaving that rule away changed the balance of Skaven a lot imo. 
Greetings,
Gerald