Group Assault, Distraction Tactics, There’s Too Many!, and (to some extent) Surrounded and Exposed teach us that Free Folk want multiple engagements; additionally the Free Folk Raiders’ Gang Up ability also benefits from the 2 on 1 action. If you are playing a Free Folk army with copious Raiders, think six or more, then you’ll be using take on Combined Assault early and often since you maneuvering space will be tight until units are destroyed.
To build off the basic Raid Leader tactics, position your units so that your opponent is forced to charge a unit, otherwise risking being charged themselves. The trap will be a supporting unit in the wings who can be activated by a Raid Leader to come in for a nasty flank attack. This unit should be out of your opponents’ threat radius, and something that can pack a serious punch. And if your opponent doesn’t fall for your trap, you get to charge him instead. Either way, you win.