It depends on the goal of the mass WO creation. If you often need to create a lot of work orders for the same group of equipment, then one option is to setup an equipment route. A route allows you to have a parent WO for the route and child WOs for each equipment that is included in the route. It is a convenient way to group equipment that are in different hierarchies and create WOs for all of the equipment at once.
It is also possible to automatically create WOs based on triggers, status changes, etc, but that requires flex.
I hope this helps!