A paraglider is an easy kill for a helicopter - just collapse the canopy with downwash. No need to waste FJ assets, just have some helo patrols along the border.
As for FJ finding it difficult to take down a helo - that's only true if you are hiding behind hard cover, otherwise anything with a sensor will see and kill you.
I was on one of the first QHTI (heli tactics instructor) courses in the UK in the late 80s, we went head to head with Lightnings who did a great job but could be forced into a head to head which they didn't like due to the guns being mounted slightly nose up requiring a dive to engage a lower target.
Then, while we were applauding ourselves an F15 called up on the radio from a CAP 15 miles away 'Puma heading 240 down the valley - you're dead' as he had radar lock on us and we didn't even know he was there.
Fighter affil in the Falklands (way past the conflict) showed terrain masking was only effective against a single FJ and as soon as there was more than one you were stuffed.