In general, this sounds like a nice QoL (quality of life) change that only has minor PvE differences, and potentially major PvP changes.
The other thought to keep in mind is whether all pets/summons/charms should do this, or just a select few? Perhaps they could be given an offensive and defensive option via the order command... they can be ordered to attack or defend a target:
- order <pet> attack <target-enemy> : Pet consistently re-targets the target-enemy after any round which they were targeting the wrong person. This could happen if someone else rescues the target-enemy to become the tank.
- order <pet> defend <target-ally> : Pet consistently rescues the target-ally if anyone is targeting the target-ally.
I particularly like this version instead of an auto-rescue by default... lets you choose how the pet/summon/charm should act, and they continue to do so until out of combat or until their orders change. This could even be made into general commands for anyone to use. (Standard rescue/target command cooldowns would apply, but it would automate them when activated.)
Thoughts?