I strongly disagree, if any of the chaotic polities cared enough to send a fleet comparable to our own after us then they could kill us by constantly striking at our planets then flying away to strike at another planet on the other side of the Trust whenever a force that had a chance of beating their fleet showed up. We would be doomed, because if we split our forces enough to respond fast enough to prevent them from taking their time to devastate any planet they struck we wouldn't have the force concentration to have a hope in hell of beating them.
The only reason I give us a chance against Turoq is because our fleet is similarly sized, if not slightly bigger, and worth more pound for pound. Which means that they are completly unable to commit enough forces to beat us that way.
I'll skip my stealth ships idea because it apparently isn't viable. Presumably because their daemons tracking our stealth ships would let them react to any move, even from inside their own territory, and still arrive there before us. Though I want to revisit it when we get around to facing more spread out multi-hundred system polities, having to prevent your weakly defended systems from getting overwhelmed should still count as a distraction and resource sink.
Right, so if the leader of a chaos warband gets delayed or intercepted then the entire thing collapses into infighting or waits for their commander(unless it's Abomination, then that only happens some of the time, or Khorne, then only the command ranks collapse into duels), this could be achieved by targeting the ship, its gellar field or warp engine, navigating and speed boosting Daemons, or the commanding individual while the ship is in warp.
Unfortunately(or perhaps fortunately) most of this sounds completly impractical, if it was possible we would lose Heroes to assasination practically every time they went through warp.
The only reason why I think this is at all possible is because it is possible to summon daemons from a distance(something illegal in the Imperial Trust), with sufficient power it should be possible to draw them away from the ship they are speeding, to bring it down to or below the speed of slow Chaos as opposed to fast Chaos.
Unfortunately even this stands the risk of getting out of control everywhere but Avernus, pissing off the planetmind on Avernus, corrupting the psykers used to power it anywhere, and being something that Chaos has already prepared to counter, because they have to occasionally use the tactic against their rivals.
@Durin 1. When you said it is possible to intercept a ship in warp what exactly did you mean?
2. How exactly would Turoq accomplish that?
3. Could we accomplish somthing similar?
My next idea is that rather than infiltrating their systems to get at their planets we send in the stealth ships and teleported pyskers to attack their raiding ships, after they've left the cover of their defenses, but in the week before they've reached their system warp limit.
I know on an Imperial ship we could just emulate the All Guardsmen Party and plant bombs in their Gellar Field Generators set to go off on thier activation, but I have no idea whether something similar would work for a Chaos ship.
4. Is it possible to sabotage a Chaos vessel in such a way as to make warp disasterous for them?
5. Do they even need Gellar fields?
6. Can it be better done by sabotaging their Gellar Fields, Warp Drive, or Plasma reactors?
My last idea is to play the player, not the game.
We need to find out Turoq's character sheet, figure out which of his subordinates are likely to lead a raid, then see if we can find any way to manipulate or exploit them, hopefully we can use precog to guide the enemy into using a commander we can trap or convince to overextend.
7. Is this idea possible?
8. I know we can't move a fleet without changing their attack target, but could we move heroes?
That way Rotbart, Ridcully, Aria and Lin could be in place to help hold off an attack, along with the Life Guard to help them survive doing this. If necessary I think this would be the kind of thing worth spending pysker lives on if it could get them there fast enough.
Edit while I'm at it,
9. Can we set tiny minefield warp exit ambushes for any raiding fleets, so long as we don't move our own fleets to make them change their plans until they're already there?
I mean, setting minefields doesn't require moving ships through the warp and letting the daemons alert their master to change their plans, and it could be hidden from infiltrators.
Edit2
We can't stop them from entering our systems, or react quickly enough to fight them there with our whole fleet.
10. Can we divine which ships will be carrying out our stolen tech, and target them as they try to escape?
Edit3
11. Can we move elite forces to the suspected site of an oncoming attack by hiding them in the merchant traffic?
Edit4
I've been spending a couple of hours reading through examples of military strategies used against a more mobile opponent, it essentially boils down to exploiting superior information sources and discipline.
In this case the Enemy is nearly as well, if not as, informed as us, and we won't find their discipline problems to dig into without divining for them.
The other strategy it seems my sources advise is to attack a site they have to defend, or fortify a base inside of their territory then raid from there until you can provoke the enemy into attacking your presumably superior forces at that base.
So this gives me more questions:
12. If we'd chosen to have pirates at the beginning, or let the Dark Eldar get out of control how would that have worked?
13. Could we do something like this?:
We send a force of privateers and stealth ships out to tow a bunch of orbital defences, minefields, habitats, and maybe a small shipyard out into an uninhabited system or other geographical feature that introduces a warp limit in Turoq's vicinity.
Then we use precognition, divination, observation of economic patterns from ships, or spies to predict the position of their civilian transport ships, presumably moving metal, promethium, materials, cultists etc.
We use this information to launch stealth ship pirate raids against their shipping from our base, striking those ships in the week between when they leave their orbital defenses and arrive at the system's warp limit, or striking them in the week between when they hit their destination system's warp limit and when they can get behind it's defences.
We don't do this just to limit their growth, if we were trying to do that we could just base the privateers from our own territory, a few months to a year is a manageable round trip. Rather we do this to provoke the enemy into attacking all of the defences we've just towed into their territory, presumably these things are more cost effective in terms of expense to construct VS expense to construct whatever number of warp capable ships is lost in the process of defeating them.
Then we replace the whole group in a different position as soon as Turoq finds them and wipes them out.
This way we play a game of 'who has the larger military industrial complex' with Turoq when the answer to that question is clearly The Imperial Trust, so long as we maintain the tech advantage, and we also become a constant drain on their shipbuilding capacity(edit never mind, crud 1.2 trillion population, If Dragon's Nest hasn't gotten much more populated since we last saw their stats Turoq outnumbers us both combined by like 3 to 1)