More efficient way to update a field using less automations?

I have a parent table with a field that is updated with an automation. Essentially, when [Formula Field X] = "Certain Condition", change [Manual Entry Field] to the value in [Formula Field X].

As changes in a formula field do not trigger an automation, my trigger is the actual event that could cause a change in the formula field. My issue is that, there are 3 major ways that formula field can change.

1. A change in a few specific fields in the parent table.

2. A change in a few specific fields in Child Table A.

3. A change in a few specific fields in Child Table B.

Right now, I have 3 automations to deal with this, each automation has a different trigger (change on Parent, Child A, Child B).

Is there any sneaky way to accomplish this with one automation?