Hit% to a large extent favors taking some gun packages over others, some targets over others (bombers), and really, I don't think it should count in the rank. The kills are what counts, if a guy is getting the job done with a poorer aim then he's flying better, right? If a guy is flying a P-47 with the heavy ammo load to get several kills per sortie, why he's paying a weight penalty.
This, not to mention that hit % favors prolonged turnfights which result in tracking shots. A pilot using energy tactics will rarely having tracking shots and will instead typically have snapshot opportunities. Snapshots are not an issue to the person utilizing them, but penalizing a pilot who fires a half a second early to make sure his rounds hit a target who's flying at a 90* deflection doesn't logically make sense.
This also doesn't factor in that these stats are inherently biased towards planes have a higher number of smaller caliber guns (read P51's, P47's, etc.). A pilot who misses the first .250 seconds of his burst and adjusts to hit his target will have more on-target time than the pilot flying a plane armed with cannons. For example, a P51 pilot who shoots for .250 seconds, missing, and then adjusts his aim to hit his target, hitting them for 1.25 seconds, has a hit rate of 83%. A pilot flying an LA-7 might also miss for .250 seconds, but any plane they hit will barely last half a second against a constant barrage of 20mm's, let alone 1.25 seconds. This means that even if both pilots have the exact same accuracy, the cannon rounds have less on-target time (as they do more damage and destroy the target quicker). This means that cannon-armed planes shoot less to destroy the same targets that MG-armed planes do, making their misses have a functionally higher stat weighting.
All of that being said, I don't feel like it's game-breaking or even a huge issue, but I don't understand why hit % is used when it's not directly tied to overall performance. Just my .02