Meanwhile, the gravitational spheres of influence of the slower, larger fragments increase rapidly in radius because most of the planet's mass is soon beyond them. So all nearby debris becomes trapped in orbit around those larger fragments. So when a large fragment of the exploded planet, such as Comet SL-9, comes too close to Jupiter, its orbiting debris cloud gets stripped off and spreads out along the main fragment's orbit. You no longer need to invoke tidal forces no stronger than blowing gently on a bit of cigar ash to break apart a comet nucleus probably several kilometers in diameter. Actually, collisions and explosions are surprisingly different dynamically.
Collisions cause fragments of both bodies to depart from near the point of impact.
This is on the surface of the larger body even if that body is destroyed by the collision. An eph-type explosion originates at the center of the larger body. A central explosion of a planet-sized body allows many fragments originating far from the center to travel along nearly parallel trajectories with similar speeds that diverge much more slowly. In an impact, small fragments tend to leave first and travel fastest, with large fragments lagging behind. Both mutual separation and the radius of the gravitational sphere of influence of each increase linearly with distance traveled away from the impact site.