If your happy with the way a layer wiggles, you can convert the wiggle expression to keyframes. Select the Layer and Transform property with your wiggle expression, then click the Animation Menu > Keyframe Assistant > Convert Expression to Keyframes.
Now just copy and paste the keyframes to all the other layers you’d like to have the wiggle, and they’ll be consistent with one another.
Another way to do this without having to ‘bake’ your expression would be to create a null, put your wiggle expression on the property you want to wiggle, then make this null the parent of all the layers you’d like to effect.
Hope this helps!