Can someone please explain “Mil Specs: When you mix it up, you count as a small gang.” in more detail.

Can someone please explain “Mil Specs: When you mix it up, you count as a small gang.” in more detail.

Can someone please explain “Mil Specs: When you mix it up, you count as a small gang.” in more detail. Mechanically the Killer will do better with Meat instead off using the gang’s size difference. Narratively the killer is doing what? I am not getting it.