[TorpX]

Adjusting just the sim file don't help much on how a Unit sinks.

I never said I adjusted it to help a ship sink. However, making ill-considered changes can interfere with them sinking. If, for example, a ship with a surface draft of 4.0 m is given a submerged draft of 5.0 m, when torpedoed, it will flood down to 5.0 m and sit there, absorbing great blows and floating all the while.

Better to set the submerged draft of the ships to 0, and let the game do it in it's own way.