I'm on my way out, so this is a quickie:
Try the following condition to see if its a JAM unit:
"JAM_WBSoldierbase" countType [_x]==1
or
"JAM_EBSoldierbase" countType [_x]==1
That covers most of the units that JAM adds, the others would be a few "crew" types and pilot types, which you could check for manually, ie:
"JAM_SoldierECrew" || "JAM_SoldierEHDCrew"
and so on.
So for example:
_isJam=false
? "JAM_WBSoldierbase" countType [_x]==1:_isJam=true;goto "jamGuy"
"JAM_EBSoldierbase" countType [_x]==1;_isJam=true;goto "jamGuy"
? (typeOf _x) in ["JAM_SoldierECrew","JAM_SoldierEHDCrew",...]:_isJam=true;goto"jamGuy"
Where _x is an object var that you are checking.