Actually the principle problem is the effect of rate of closure on delay.... Delay physics becomes an important component in how to adjust your tactics to the game environment. This is especially true of gunned buffs.....
Consider....
Two planes P1 and P2 at True Distance X at N Knots of speeds with plane P1 in the lead and P2 in pursuit. Assuming a uniform delay of 1 the following holds true:
Perceived Distance (P1) to P2 = X + N (approx). Thus at a true distance of 1000 yards and at 300 kts the plane pursuing you looks to be 1300 yards away.... Consider also... Perceived Distance (P2) to P1 = X-N (approx). Thus at a true distance of 1000 yards and at 300 kts the plane you are pursuing looks to be 700 yards away.
This is the infamous "rear lag" which causes many pilots to explaim in disgust "I was taking hits from (some silly distance) away!"
Note that increased delays and differing airspeeds can alter the above equation such that the true equation is something like PD(P1)->P2 = X + ((N1/2)*Dp2) + ((N2/2)*Dp1) where N1 is the speed of P1 and Dp1 is the Delay of plane 1.
This has a dramatic effect on gunned buffs because of the requirement to achieve local hits before host hits will be considered.
Long before a gunner can engage a fighter closing on his 6 effectively that fighter can put a large number of hits into him. Additionally if the fighter is wary, does not mind burning E, and is aware of the above relationship he can reduce his rate of closure such that the bomber is destroyed while only giving him minimal exposure to the gunners.
Note however that the solution for gunners is not as bad as it is for fighters. Since the gunner receives his position information delayed from the pilot of the buff
PD(P1g) = PD(P1) - ((N1/2)*Dg)
So, the optimum solution for the gunner is for the delay of the bomber pilot and fighter pilot to be low while his is one higher (2). This will enable him to get local hits, and thus have his host hits considered, but will narrow the window to get "legitimate" host hits as the closing fighter overtakes. However because of the larger hit bubbles and the tendancy of overtaking fighters to explode on the way in this is not so much of a factor. It does become a factor however in the case of closing or high deflection shots. In these cases the higher delays force the gunner to play "guess" warrior, and has a major negative impact on his accuracy.
There is of course, a better solution. It is preferrable, from the point of view of the gunner, for the bomber to close on the fighter in a headon. This aspect is the MOST advantageous for gunners because of the elimination altogether of the effect of rear lags as well as the gunners capability for all aspect shots! In general a gunner in the upper turret of a B17 can destroy a Spitfire in a single such headon pass about half the time.
In addition this high closure rate adds the onus of G - Effects to the fighter pilot, the effects of which the gunner is immune to. A fighter trying to follow a relatively small aspect change on the part of a bomber is forced to perform a high G correction which my black him out and negatively effect his gunnery, all while the gunner blazes away at him.
So, a perfect illustration of how game physics, in this case, mandate a completely opposite tactic from the historically accurate case. There are no doubt others (for instance the best way to engage a tank the ground is not with another tank, but with a flakpanzer) that are also strange, but none that have such a huge effect on gameplay.