That's the thing, telling a Heron to escort, at least with a steady officer, makes it act like it's some kind of brawler that can withstand hell when in reality it's just a fast, paper thin ship.
The problem is this: With 3 Xyphos, a timid officer would be the perfect choice, stays far, and sends the fighters to escort allied ships (at least that's what should happen, haven't tested in practice).
But using a timid officer makes it impossible to use bombers, and fighters aren't best used as permanent escorts, attacking is needed, especially to quickly dispatch frigates.
What would solve the issue is being able to change whether a carrier ship is considered as a combat carrier. I mean it's probably easy to mod, but I don't want to screw up anything AI related because of this.
Maybe add a new hullmod that boosts fighters a bit, reduces the ship stats like shields, speed, etc... And removes the combat tag if it exists?
There's also the possibility of letting us switch AI personalities when we want, outside of combat. It would make less sense roleplay wise, although I personally don't care about this, I see it as more practical. Right now it's better to already envision your late game fleet and pick officers based on this. For example you can get a reckless officer with all the armour skills and put him in an Onslaught later on, works well. But you already have to be familiar with the game to make those decisions.
Edit: Apparently if you give bombers to a carrier it will ignore the personality and use them as they should, which is good, but also means that you should not pair bombers with support fighters within a single carrier.