Not quite right explanation I am afraid.
As per
@Zafer has stated, the bigger the mass at terminal stage the faster the missile hits it’s target
If you check the terminal velocity formula:
View attachment 80404
The cross section of the missile is important too. More perpendicular the missile approaches the better as it would decrease it’s silhouette.
As a generalisation for a ballistic missile, 60-70%of its mass is fuel. When the missile is in it’s ballistic downward motion it will have depleted it’s fuel
if you fire a 6000km range missile to a target that is 3000km away. You fire it at a more steep angle. It still depletes it’s fuel.