This is a good and appropriate improvement. Just even carrying a barrel of oil, let alone throwing it, should not be an easy thing. Apparently a lot of people have no idea what is a barrel and how big and heavy and bulky it is.
That said, the very presence of so many oil and powder barrels just lying around for anyone to take is itself a problem for me. The number of available barrels needs to be cut back, and those that are available should be harder to take and harder to use in the sense that people should notice what you are trying to do and react appropriately to it.
total agreement
It makes no sense to carry or throw barrels full of oil or water.
Rolling them may be fine though.
Prof. Dr. Dr. Mad S. Tist 
