The perceived problem is the maximized "cone of fire" effect.
Like Karnak said some time ago HT himself clarified that the buff guns don't just converge automatically at a single point, with the so called "laser-targetting" accuracy. While the explanation was a bit vague, since IIRC he didn't exactly explain how the guns converged to what accuracy, I think we can loosely assume that all the buff guns will just 'try' to shoot at the point where the current defensive gunner is aiming/firing at. It won't EXACTLY converge at a single point, but all the rest of the gunners will fire towards it.
Now, the "problem" in my theory, if we can agree there's such a thing, is this:
Bear in mind that while a nose/centerline armed fighter armament is much more powerful and efficient when it comes to destructive power, the actual ease of hitting the target is better with wing-armament due to the shots spreading out in a so-called "shotgun effect". The P-38s with 4x .50s in the nose, will always hit grouped shots that are deadly. However, the same 4x .50s with the P-51B, won't be as destructive due to the convergence problem, but will be much easier to land 'pings' on the target.
The problem with the wing-armament is that armament like 4x .50s or 6x .50, or sometimes even 8x .50s for that matter, isn't as efficient due to the nature of the shots spreading out. The RAF, moments before the opening of WW2 IIRC, used a standard convergence pattern which spread the shots out in a "box" pattern. However this idea was quickly discarded with the actual advent of combat, as WW2 fighter experience proved that spread out shots are basically worthelss. It is for this very reason a much more powerful HMG like the .50s, still needed 6~8 guns at the price of all the extra weight.
However, imagine the "shotgun effect" of a three-plane formation of bombers this time. Look at how all the gunner positions vary slightly in its placement, and then consider another group of variation in placement due to three bombers flying in a Vee formation.
In a word, it might actually be easier to evade buff guns if they truly did converge at a single point. In this case, if the defensive gunner doesn't aim the gun exactly right, most of the bullets will miss the target. We now know that the guns don't EXACLTY converge at a single point. However they do fire at the target direction up to certain accuracy.
This means, in essence, a mungo shot-gun effect of easily 10~20x 50cal HMGs are now brought into effect by the buff formations (!!!) Instead of all guns converging at a single target point with slight variations due to dispersion, 10 to 20 .50cals are sprayed towards the target at an very large circular pattern. If the general aim of the defensive gun position the player is sitting at is reasonably good enough, in effect a big circle of .50s are sprayed in the entire area. In this case the number of .50s pointed at the target is so numerous, that shots being sprayed are not much of a problem.
Assume you are trying to hit a B-17 formation from the left in a sweeping pattern. Add in the fact that the buff guns fire through the drones to what is explained above, and what you'll be facing is a "shotgun" that fires rounds at 800~1000rpm, with a firepower equivalent to that of 21 (count them.. twenty-one!!!) 50cal guns.
Yes, twenty one. Two from the ball turret, two from the tail gunner, two from the upper turret, and one from the port side waist gunner... multiplied by three, since the guns fire through the drones and doesn't have a "halt fire" or "interrupter gear" angle.
Scattered fire that is out of convergence from four 50cals may be shrugged off... but a scattered fire from twenty-one 50cals with a maximized cone of fire is just plain deadly. We have veterans claiming they can kill buffs easily, but that is purely situational. Against experienced buff gunners in a three-plane buff formation the only safe way is a coordinated attack with numbers of at least three interceptor planes. IIRC, it was Urchin and Toad who tested this out, with Toad claiming that buffs aren't a problem. The results, I believe, was all Urchin defended all three buffs, with only minor damages to a few of a drones.
In a word, imagine a situation where there are three P-51Ds behind you, at the exact same interval and intenisty, all of them aiming at you generally, and spraying all their guns non-stop until ammo runs dry. That's what going against buff formations is like. Either catch them offguard, or meet a very inexperienced gunner. Someone even remotely experienced in defensive gunnery, and the interceptors are basically toast.
IMO, some ideas without the introduction of "Otto", to solve/ease this problem;
1) Stop buff guns from firing through other planes in the formation
This one is an absolute. This will at least make it possible for the interceptor plane to cut down on the number of guns pointing at him.
2) Add a 'randomization' factor that greatly reduces the effectiveness of all the hand-held guns on board
With the suggested randomization factor, all 'slaved' hand-held guns like the waist guns, will be firing at the general direction of the target point of the current defensive gun position the player is manning, but in many cases their dispersion will vary upto great levels.
3) Add vibrations to guns
The mechanized guns should have a small vibration effect. The hand-held guns should have a big vibration effect.
4) Add a varying interval of gun fire.
When the guns from the currently manned position begins to fire, all guns slaved to it will start fire... but after that they will fire at varied intervals. Instead of acting like a one big shotgun with 10~20 barrels, they will fire at random intervals as long as the manned position keeps his trigger down. This would sort of depict individual gunners on board stopping fire, correcting their aim, and etc etc..
