I think using that script will produce dead units with the same animation.
That is, if a unit is dying with its face on the dirt, all other units will be the same too.
I think you should add a fading (black in) at the start and put the sound volume to 0 (to avoid hearing the dropping body sounds).
init.sqf
put the following at the VERY START of init.sqf
titleCut ["","BLACK IN",10];
//10 seconds to fade in
0 fadeSound 0;
sleep 5;
0 fadeSound 1;
there might be a better way for example, selecting random dying anims out of an anim array..
but at the moment, I could only give you the above solution...
Regards,
Haroon1992