Normally you lose 3 movement when you step next to a unit with zone of control (like melee units).

But if you take 1 unit out of the group in a hex next to the army, you only lose 1 movement.

Then, you can move the remaining army into the 1 unit.

All in all, you get to use your entire movement fully avoiding their ZOC.

This army started in the forest in the west.