Falling Onto Another Creature (Objects & Creatures)

Greetings D&D Beyond Community,

We had a situation recently where an object was dropped onto a creature they were fighting from the ceiling of a cavern (player had spider-climb).

We discussed how to resolve the damage and settled on using the standard Falling Damage from the PHB, but instead of having the damage affect the object (in this case an 8" diameter rock) it affected the creature that the object was dropped onto.

Now, I know that the DMG includes the Improvising Damage section which lists examples such as:

• Hit by a falling Bookcase: 1d10 Damage
• Hit by falling Rubble in a collapsing tunnel: 4d10 Damage

I understand that if a creature is falling they are hitting the ground which is typically a flat surface and the 1d6/10ft of bludgeoning damage seems straight forward, and as the DM if I had a creature falling onto some jagged rocks below, the damage might change, but we'll stick with the standard and it works for most situations.

How do you as DM's handle the following:

• Objects falling onto a creature (do you just use the Improvising Damage table and decide what seems closest to the situation that you are dealing with?)
• Creature falling onto another creature (do you use the standard Falling Damage, but apply the damage to both creatures?)

Thoughts?

I think, but I'm not sure, that in the case of creature falling on creature, they both take half the falling damage, and the creature that was fallen on must also save against falling prone. Both creatures might take the full damage though.
For an object falling on a creature, I would use the 1d6/10ft rule, but maybe adjust the die size or the number of dice based on what the falling object is.

In general, I use standard falling damage rules and the damage is split between the two targets (the faller and the fallee)