"To fire or not to fire, that is the question?"

[Gordons HQ]

I agree with most of the above, I think from the experience I have had with the game it's sometimes best to hold your fire in defensive positions. It often depends on circumstances of course and if in good bunkers or pillboxes then it's oftenl worth opening fire with a reasonable chance of survival.
However sometimes to wear down the opposition it seems better to hold fire and let the enemy get further fatigued when attacking.