It would be fun if depending of the size of the ship the final explosion would be "random". In some cases the ship would just be left floating in space wrecked without any explosion. In worst case bigger ship would cause a huge explosion.
This would be interesting since as crazy I am personally I tend to run my nose of the ship near the enemy and most of the cases I end up taking damage because I am too close to exploding ships.
This would add a tiny but crucial tactical element to the game. In other words, you would want to get from near the enemy ship before it gets destroyed.