It's much easier to hunt 300 acres than 21000. On 300 acres (which is slightly less than 1/2 squre mile) the odds of seeing a deer is much greaqter that the bigger parcel. Hence it would be harder to hunt the bigger place
I'm guessing that you live somewhere in the east because that is a pretty ignorant statement. You can't compare "fenced in" areas by land mass. Size isn't as important as terrain.