I didn't order Fleet Defence to make a suicide run IIRC?

[Shadow_rainbow]

The picture describes the situation:

There are some fighters and corvettes (and a destroyer in a second group not visible in the screenshot) at Ship Defence duty for my destroyer heading for an enemy installation. Group assignment is displayed in the right panel, Subordinate Control section.
When the group starts arriving to a bit longer than the main battery range, the ship defence force starts throwing themselves onto defence platform (indicated by blue target cross icons around the closest defence platform). The rest is not yet engaged, but they will once they get in range.

This is clearly not the expected behavior. Ships assigned to defence are supposed to protect their assigned target from attacks, not engage in bombing runs (besides, they are not even equipped for such a run) -- unless ordered to do so directly and implicitly. I've seen it time and again, light ships on defence duty committing suicide on defence platforms, stations and capital ships.
There is specific order for exactly that, I believe. 'Bombard for commander', specifically. But clearly not 'Defend commander'.

To date, I have found no way of dealing with that. I have to literally remove them from their defence duty, leaving the ship open to light craft strikes (thankfully, these are disorganized even en masse -- though that is not a good thing, either) and either assign them to 'Follow', passively exposing themselves to attacks of approaching craft (unless ordered to attack those directly), or assign them to fly away to some quiet spot to save them.

Perhaps there is an ingame behavior script that forces them to keep away from targets they are not fit to deal with -- or at least not attack those specifically? Maybe a mod of some kind?

[TheDeliveryMan]

Attack for Commander: Attack the target of the commander
Intercept for Commander: Attack S/M ships in radar range of the commander
Bombard for Commander: Attack L/XL ships in radar range of the commander
Defend Commander: Attack everything that shoots the commander

Given the above rules and knowing how efficient Kha'ak are against fighters, I would expect the escorts not to survive such a mission.

[vvvvvvvv]

The picture describes the situation:

Because Khaak use beams which are hyper efficient against fighters, this setup will cause you to lose all fighters.

"Defend" means "try to murder anything that attacks commander". ANYTHING. Anything dents your armor they'll try to kill it. Which is why you normally use intercept (only attack fighters in range) or bombard (only attack capitals in range).

There are also issues with your turret configuration.

For turrets normal config:

Flak, L beams, Pulse: Attack fighters first.
M beams: Attack missiles first/missile defense.
Plasma: Attack capitals only or attack capital first.

A single syn should be able to clear out a hive, slowly. But you'd want its turrets to have L beams and L plasma (paranid). Then attack defense platforms one at a time with Syn's main gun.

[GCU Grey Area]

I keep my S/M interceptors on a carrier & place that about 40km behind my destroyers during station demolition work. Close enough that they will defend my destroyers from enemy drones and/or fighters, but far enough away that they only engage drones etc which have flown outside the station's turret range.

[Shadow_rainbow]

Attack for Commander: Attack the target of the commander
Intercept for Commander: Attack S/M ships in radar range of the commander
Bombard for Commander: Attack L/XL ships in radar range of the commander
Defend Commander: Attack everything that shoots the commander

Given the above rules and knowing how efficient Kha'ak are against fighters, I would expect the escorts not to survive such a mission.

Thanks. Although during these days I've found a mod that addresses this issue among others, for the time being I will still try setting up Intercept orders for lead ship escorts instead (since that mod is apparently set up inside more complex mod infrastructure). I've tried Intercept some time ago, but it has the problem of subordinates going for any ship in radius, including medium haulers docked at station (which caused them to run into station defence anyways).

I have expected 'Defend' to work as 'Intercept', but only in relation to fighters and corvettes, which seemed most logical.

As for Khaak beams, I did end up losing a few fighters to waves of reinforcements, reloading and then just sending all the S/M ships away and going through with 2 destroyers. Worked out quite well with no damage at our side. I believe I would have to load more fighters with flak cannons to deal with flying pyramids in time in the future.

[Shadow_rainbow]

"Defend" means "try to murder anything that attacks commander". ANYTHING. Anything dents your armor they'll try to kill it. Which is why you normally use intercept (only attack fighters in range) or bombard (only attack capitals in range).

Yes, I find it extremely strange. It's not like defense platform will warp to zero on top of us, and losing light defense force to soak destroyer's main gun fire in the 'Arm the ejection seat, you're the last flare' way doesn't really have any sense. Sadly, Intercept has its problems with targeting small and medium stuff that is not trying to attack commander.

Thankfully, during my searching after this post, I have found a mod that (as declared) modifies this behavior. Didn't try it out yet, so can't say if it's still relevant or playable. It also seems to rely on some prior mod infrastructure which I haven't had the time to figure out yet. At least in description it is said to force fighters to respect threat ranges of big guns unless ordered to do otherwise.

There are also issues with your turret configuration.

For turrets normal config:

Flak, L beams, Pulse: Attack fighters first.
M beams: Attack missiles first/missile defense.
Plasma: Attack capitals only or attack capital first.

A single syn should be able to clear out a hive, slowly. But you'd want its turrets to have L beams and L plasma (paranid). Then attack defense platforms one at a time with Syn's main gun.

ATM it has anti-Xenon loadout, so I don't have to worry about missiles. Had to send fighters away for this engagement anyway. Cleared the hive with only the double destroyer group.

As for plasma turrets being ordered to attack capitals first, I'm not sure about that. I have read that it can lead to destroyers ignoring their main guns range and going in close (to plasma turret range) instead.