Complex sentence: The volume of the vulcanoid zone is very small compared to the main belt of asteroids, and collisions between objects in the vulcanoid zone would be frequent and highly energetic, tending to lead to the destruction of the objects.
Split into simpler sentences: The volume of the vulcanoid zone is very small compared to the main belt of asteroids. Collisions between objects in the vulcanoid zone would be frequent and highly energetic, tending to lead to the destruction of the objects.