A whole gaggle of fighters latching onto a single opponent might be realistic, but it's also a rookie mistake. It's just stupid for a whole squadron of supposedly "veteran" or "ace" AI to be trailing along behind you in a stern chase.
If you've got the advantage of numbers on your side, you "box" the enemy by sending off pairs or sections to cut off his lines of retreat or to try to hit him with fire from multiple directions.
At the very least, if you're chasing an opponent you should send out a couple of sections in a line abreast so that there are more guns to bear should the enemy decide to turn.
While I'll reserve comment on AI behavior until I get the 4.11 patch, it seems to me that AI could be further improved by:
1) Having fighters target the lead bomber of a "box" (group formation), or lead bombers of each element of a "V".
Historically, this was important because the "command bomber" often decided when the rest of the formation would drop its bombs, and the "lead bombardier" aboard the command bomber was also likely to be the most experienced (hence, most accurate) bombardier in the group.
2) Have fighters cooperate when attacking enemies, rather than "every man for himself".
While it would be too much to ask for full-developed and historically accurate section, flight, squadron and group tactics, some attempt to split defensive fire with simultaneous attacks or to cut off an opponent's line of retreat would be easier to model.
3) Trying to better model historical doctrine, such as the reportedly low initiative and focus on formation keeping by early war Soviet pilots or British early war 3 plane fighter formations.
4) Make wingmen slightly smarter and have more options for your wingman.
Right now, wingmen slavishly follow their leader and almost never shoot unless an attacker makes the mistake of getting between the lead plane and the wingman and attacking the lead.
By contrast, if you tell them to "attack my target" they're in competition with you for the kill, and sometimes accidentally shoot you!
Wingmen also don't immediately report enemies on your tail, nor do they tell you what to do to get them off.
If asked, a good wingman could be ordered to get into a position to cut off an opponent's line of retreat or bring him under fire when he turns, in the classic "drag and bag" manuever.
He should also tell you to break right, left, up or down to avoid an incoming attack, and possibly even attempt to use a "drag and bag" himself.
Likewise, you should be able to order your wingman to take the lead, or act as "bait" so YOU can try a drag and bag:
Basic commands:
1) Break Right.
2) Break Left.
3) Keep steady (i.e. go straight).
4) Dive.
5) Climb.
6) Hold course (i.e., keep doing what you're doing).
7) Chop the throttle/try to get the enemy to overshoot.
Cut off - i.e., try to get a position 60-90 degrees off the enemy's current course so you can get a shot at them as they turn.