I've come up with a manual solution but that's too much of a hassle. This is basically how I approach it:
Select the objects I want to scale another object to > Join them > Set origin to: Origin to Center of Mass (Surface)
Copy the dimensions > select the target object and paste the values in the respective Dimensions field.
- With the target object still selected, add joined objects to selection > SHIFT + S = Snap: choose Selection to Active
4... Bunch of actions needed to separate objects and reset their original pivot points and what not...
There must be a quicker way to do it.