Replace The Beams With Rotten Timbers
Disrupt the enemy's formations, interfere with their methods of operations, change the rules in which they are used to following, go contrary to their standard training. In this way you remove the supporting pillar, the common link that makes a group of men an effective fighting force.
I used to work at a company that was acquired by another. The company that acquired us was much smaller in size but much more dominant in nature. They swiftly changed most of the structures my old company used. In order to destroy any resistance, they even took out the main intranet site, with the search function and list of department sites that everyone had relied on. Then they got rid of that department's staff. They continued this approach with any business functions my old company had had in place to handle departments such as security, architecture, etc. With strategic groups gone, and their collective business knowledge with it, the new company was free to do as it wished, and it nearly succeeded in destroying/selling off most of the old company.