Nearly outdated stuff that could be useful. (Potential improvements)

The idea is that it has a bar that wears out when healing units that consume resources when used.
This bar would reload faster if there are surgeons inside, but to use it requires food resources and coins.

Or you could activate some type of ability in which you heal a certain percentage faster than usual, but that will spend resources and heal anywhere on the map if the units are at rest, or heal them quickly if they are close.

The general idea is that the ability to heal may be more effective, but it is not free.