Maybe it is possible to create two virtual bombs/effects in the same *.dp file ?
- one with large explosion-radius and
- another much heavier with very small radius?
Or set the aircraft up as weapon/rocket and the warhead as own bomb, too - so the two different weapon-effects are actually in two different objects.
And I have another idea, that might help: The probem with dropping objects is, they drop separately.
But the M10 rocket launcher by Dbolt was made out of different sub-objects for example.
The modelfile itself has only entries, which call the other library-objects.
So it should be possible to make a new weapon "Mistel", whichs modelfile calls your stripped Ju plus the warhead and maybe the struts on top of the Ju (if they drop with the Mistel - I don`t know).