Well my understanding of LUA is near 0, but I know how to help myself with SEXPs, so here's a part of the solution I was thinking of (I did this when I actually ran into the fighter issue, with comm menu and wingmates being depicted as departed by the HUD):
( set-object-position
"Alpha 2#Replacement"
( get-object-x "Alpha 2" )
( get-object-y "Alpha 2" )
( get-object-z "Alpha 2" )
)
( set-object-position
"Alpha 3#Replacement"
( get-object-x "Alpha 3" )
( get-object-y "Alpha 3" )
( get-object-z "Alpha 3" )
)
( set-object-orientation
"Alpha 2#Replacement"
( get-object-pitch "Alpha 2" )
( get-object-bank "Alpha 2" )
( get-object-heading "Alpha 2" )
)
( set-object-orientation
"Alpha 3#Replacement"
( get-object-pitch "Alpha 3" )
( get-object-bank "Alpha 3" )
( get-object-heading "Alpha 3" )
)
( set-object-position
"Alpha 2"
70000
70000
70000
)
( set-object-position
"Alpha 3"
70000
70000
70000
)
( add-goal
"Alpha 2#Replacement"
( ai-warp-out 89 )
)
( add-goal
"Alpha 3#Replacement"
( ai-warp-out 89 )
)
( friendly-stealth-invisible
"Alpha 2"
"Alpha 3"
)
( ship-stealthy "Alpha 2" "Alpha 3" )
3 things remain that are not included in this:
-the ship that jumps out as decoy has to be created first (like ship create, which would take the place of set-object-position and set-object-orientation)
-the decoy needs to receive proper speed (i.e. taking over the values of the actual ship) - this could be done via ship-maneuver.
-the visible warp could simply be fixed by sending the ship 1000km away. That's not a problem EXCEPT for the player ship, which then self destructs in such cases.
Also, this script has the advantage that you can easily define the position and vector where a ship is supposed to re-arrive through waypoints, something that is elseway only possible through using an invisible blip, having it face away from the target, and than spetting the ship#2's arrival parameters to "in front of", what is mildly said not user-friendly.
The way it works for fighters is fine for me, though.