I hunt my own property in Washington too. My situation is different because one "neighbor" is Weyerhaeuser and the other neighbor will hop out of bed and grab his 4-wheeler to help me get the dead deer in the garage.
Blacktail deer just aren't all that big usually. I think if you drill one in the A-zone with a "heavy enough" arrow with any "good enough" broad head, they will die pretty quick.
I think where two blade, heavy broad heads offer an advantage is when things go awry on deer, and when you are trying to kill bigger animals.
Last deer I shot was with a 300 spine arrow, with a 100 grain brass insert, topped by a 175 grain Grizzly single bevel. I was in a tree stand. The shot was slight quartering away. The arrow went in the back 1/3 of the left side rib cage, came out the front 1/3 of the right side ribcage, and broke the right front foreleg. That deer was easy to find.