Trotter, a single wirble can clear the entire area around it before any of them can get a shot off. It's lethal from a single ping on any part of any fighter/attacker out to 2.5k (and I've had wirb tracers bracketing my plane left and right by a hair's width so far out from the offending GV that is 3-4k out), the speed at which it fires and the number of guns, the super powered rounds they fire, means they can put up 4 walls of ammo so fast that you can't avoid them, fly between the rounds (which for any other gun is a weakness) or even get near. You can't even rocket, bomb, or strafe a wirb without it killing you before you're even inside drop/fire range.
It is, to put it bluntly, bull****.
It fires too fast, for too long, moves at super retarded speeds.
It's a GV that's taken up well over 90% of all aircraft kills in the entire GV family, is used and abused repeatedly and at every fight I see in the game, and the performance specs are way way above what they were in real life.
So yeah, perking it would be the best solution but fixing the damned uber fire rate and specs would be good as well. Even with those fixed we'd still see enemy wirbs parked on friendly runways at all times like they do now.
If all else fails, they should simply remove the secondary fire button. Make it ONLY EVER fire 2 guns at a time. This simulates reloading the second pair of guns while the first pair fires, and vice versa.