Yeah. I only did copies of the capital ships. Warp-effect + set position wouldn't work for them because they need to pick up speed and they wouldn't vanish into the effect.
If you look in the mission in FRED, you will find ships called Cretheus#1, Cretheus #2, Cretheus#3. Anything after the # will be ignored by the game, so you can use that to keep track of ships in FRED. So just after I told them to warp out, I used the copy-ship-damage sexp to the next ship that would be coming out in a few seconds.
With fighters though, I just set position behind the player. You won't see them warp, but I figure you wouldn't notice anyway. Wait, now you will! Noooo...
Battuta: I could've used the subspace sexp but I figure you're jumping 50 to 80 klicks so your trip inside subspace would be a few milliseconds. Hardly enough time to notice it. Your own implementation was a much longer distance, so I could understand the use of it there.