I think the best way to have some resistance soldiers appear as a result of sovSold1 dying is to use the getdammage command in conjunction with the createunit command. For example:
Create a script which loops from the beginning:
#LOOP
? (getdammage sovSold1) > 0.9: goto "SUB"
goto "LOOP"
#SUB
"soldierGB" createUnit [getMarkerPos "spawnmarker", guergrp1,"", 1, "corporal"]
"soldierGB" createUnit [getMarkerPos "spawnmarker", guergrp1,"", 1, "corporal"]
"soldierGB" createUnit [getMarkerPos "spawnmarker", guergrp1,"", 1, "corporal"]
"soldierGB" createUnit [getMarkerPos "spawnmarker", guergrp1,"", 1, "corporal"]
exit
You could replace sovSold1 in this script with _soldier, so that the script can be used with more than one soldier.
The 'spawnmarker' can be placed wherever you want the guerillas to appear, and 'guergrp1' is the pre-defined group name.
The script can be run from the init.sqs
Hope this helps
Gruntage