My view one invaders: Some of them I fight are extremely nice (they will let me fight of the other enemies, and then beckon me over to fight) while, mainly the 'Wraith' types are pure assholes, taking advantage of any lag...and then letting enemies finish me off (at least have the decency of killing me yourself!)
When I invade for Dragon scales, I generally stick to a distance, analyze the person, and if they are ready, we fight. I win some, and lose some, but overall have fun. As a courtesy, I always bow before, and after, the fight =p