They are both intervening, one via a buff and one by actually rushing to the target. You could argue Cover is more of an intervention than either of them.

It's a bit of a mess. The names are becoming increasingly meaningless, especially with how SE has repurposed the same actions over and over without renaming them in recent expansions.

The names serve primarily as a reference to the source material the Job is based upon - old final fantasy games, mythology, legends and historic events. Getting rid of them might take away from the spirit of the Job so I understand not wanting to lose action names.

Fortunately the names don't matter too much. Most of the time, we just see the pictures on our hotbars and click them.