[Pyros]

Perhaps the following text from Andy G. will help you, better understand how the Z-fire works under WinSPWW2:

Mobhack said:
Z fire is "spray and pray" usually used to beat up an area throughg smoke (no LOS) or as "recon by fire" on a suspected area. It is speculative fire, and hence less effective, with probable max effect of pin, rarer to hit and cause casualties. It should be a rare form of fire (barring USA type shooting up areas you suspect of having hidden troops in). It causes "friction of war" rather than a load of casualties - but sufficient pins of say a herd of infantry screened behind smoke, may well break the attack up as some units will not rally, and so will remain pinned and so will enter battle later.

cheers,
Pyros