Hmm...okay, I gotta chime in here.  I can certainly understand the worry about low level aircraft operating beneath radar being a threat, and it certainly did lead to the demise of both the Sheffield and the Atlantic Conveyor.  However, both were sunk by Exocet missiles fired from modern Super Etendard aircraft capable of low level speeds in excess of 700mph.  And a single Exocet weighs in at 1,881 lbs...surely beyond the capability of these aircraft. 
I can also appreciate the "stealth" concept, but these aircraft are not stealthy in the least with all the flat surfaces and exposed engines, etc. 
What does worry me about these Bavar 2's is that they can probably be built cheaply, and in vast numbers...going along with their stated intended tactic of using them in "swarms", or as some are guessing, kamikaze aircraft.  Even so, without the benefit of heavy firepower, speed, or even enclosed cockpits I still have a hard time believing them to be a threat.
Now, loaded with some sort of chemical or other unconventional weapon...maybe...if they can get close enough.