Is it true that under "normal" weather type days, like low winds, due to EWR's runway configuration, they pretty much determine what arrival/departure flow of both LGA and JFK?

Also, does LGA have the smallest chunk of airspace for the approach controllers to work with? I know, it's the "smallest" of the NY airports. But the 2 years I was based there, it was still pretty busy. Especially before the March 01 "slottery".