Why should a "thoughtful" killer be more evil than a "thoughtless" killer. I think the method of killing and the number or killings are more important than how much planning was involved. Also justification should be considered. We go to a great deal of effort to plan an execution, is that evil ? Our military goes to great efforts to plan, train, manufacture weapons, practice effectiveness, is this a trait of evil ?
They are practicing ways to bring about a desired outcome with as few deaths as possible. If it did not matter, the whole force of the United States' military would destroy a country in a few seconds. That's why they train. They train to hit their target and nothing more.
To even insinuate that their could be linkage to the US military forces and evil is reprehensible.