Do I need to feel like I should take a backseat to these guys who have been hunting there? or should I just "have at it" and treat the property as mine since I have every right to be there?
You already know the answer. Treat them the same way you would expect to be treated if you had been there and they were the newcomers.
Plain ol' hunting ethics!
If they dont show any hunting ethics then it's time to kick a** or chew bubble gum.
What ya gonna do?