Too man y times i seem one get scarfed by 10-15-20 planes. we hit it with bombs, rockets, .50 cal, 20mm, 30mm. Just wont die that easy. As far as the ack, you have one than one shooting at you.
I kill them all the time with a few shots from an IL-2, or a single shot from a tank. I dont take videos of it cause I dont think killing a wirbel is worthy of a video. I do however take videos of killing Tigers and I'll show you a few passes of what was a long ordeal, killing a overturned Tiger , driven by FBBob, in LWB last night. I went thru two IL-2s full of cannon and thats not even counting the bombs dropped. A wirbel would simply have taken a spritz of MG fire and a few hits of cannon.
They were, are, mounted on a tank chassis. You shouldn't expect to kill them with fighter rounds designed to kill other fighters. But you can at least put them out of action with 0.50s. Try doing that against a Tiger.
The Wirbel did not have a powered turret like it does in AH, and consequently its rate of traverse was significantly slower than what we have. What's more, the ammo came in small clips and had to constantly be reloaded, and so the practice was to only fire two guns at a time.
What about all the other GVs you'd have to do the same with? All the aircraft are modeled in ridiculous "easy mode" too. When I get this video uploaded I'll show it to you, even tho it only shows the end of what was a long ordeal. FBBob started off with a wirbel watching his back at the spawn. Had the flak stayed with him he probably never would have gotten killed, and without free wirbels the GV'ers would suffer heavily.