The problem that the parasites have is that they have to be correct every time they go up to someone and try to force the issue of food or other supplies.
I would suggest that they would be wrong early on and would be taken off the plaing field.
Yep. Attrition is going to get them eventually. These aren’t all going to be dynamic entry SWAT raids. You might find yourself and your team being engaged from long range by multiple bogeys in organized units with comms, night vision, even thermal.
Our soldiers are used to excellent logistical and air support as well as superior weaponry. Only a small band of special ops groups are truly trained to operate on their own for a long period of time in the above mentioned situation.
The parasite route will be high risk and hit and miss. And there’s no rule that says they couldn’t follow you back to your lair and rip you a new a** too.