> This is wrong.

No, it is not. Even hiding in the hospital make the hospital loose its protection (see here: https://lieber.westpoint.edu/legal-protection-hospitals-duri...)

This piece in particular:

> The ICRC’s Commentary cites as examples “firing at the enemy for reasons other than individual self-defence, installing a firing position in a medical post, the use of a hospital as a shelter for able-bodied combatants, as an arms or ammunition dump, or as a military observation post.” It also states that “transmitting information of military value” or being used “as a centre for liaison with fighting troops” results in loss of protection.

> Sheltering soldiers, even using floors as war rooms for planning is not enough.

It is enough for the hospital to loose its protection.

> Any response taken against a hospital must also be proportionate to the harm.

This is completely different question though: proportionality of response vs. protected status of various institutions and buildings at war.