I'm not saying they'll be a breeze... Ofcourse intelligent enemy can even train rats to be granade carriers.
Still a combo of fragmentation airburst granades & shotgun buckshots can be much MUCH cheaper counter to blunt them to significant degree, especially when they'll have to close in for hit. 1000 swarm-drones vs 100 shotguns & training regimen have heavily skewed cost ratio.
Armenia was hardly a proper case-study.
There is a natural order of progression to things
First one has to prepare to detect a target
Then isolate and track a target
Then bear his weapon on to the target
Wait for the target to get in the kill zone of his weapon
Then ensure hit on the target
Imo Humans with airburst grenade launchers & shotgun buckshots will fail miserably.
Aerial targets are always hard to him .
These drones even though they are commercial drones by the look of things , in a swarming configuration will overwhelm a human or a no of humans , things will happen so fast that human operator reflex will fall short.
Things are easy to imagine but a soldier on a look out for drones sweeping out of the sky will be on tender hooks psychologically.