My experiences with Zoney are that he is a high-altitude bomber interceptor / prowler / hunter / bastard.
I am not saying he does not or has not picked fighters, I have just never personally seen him do it.
What I HAVE seen him do is glide in (like a bastard) and shank a wing or hammerfist my cockpit while I am busy reading Forbes or smoking model glue.
On the other hand, he doesn't shy away from guns blazing at him, and I have oiled/partially dismantled his fighters on occasion and on (rarer) occasion sent him packing!
He does a great service for the game as a whole, being one of the unsung heroes (that jerk Snailusche also comes to mind) that collect the town-porker taxes on a regular basis.
Bomber hunters benefit the AH ecosystem by:
1. Taking the milk out of milk running; this makes running a lone Mossie XVI or even a formation of B-17s a more exciting proposition, or acts as a check against the ultimately timid who will just bail and quit.
2. Putting a check on lone strat runners; with the strats being hugely helpful to rolling bases this speaks for itself.
3. Keeps base porkers from simply climbing to 20-30k to end your furball fun. They either give up or fly low where you can have your way with them.
I haven't flown bombers for several tours now, and hence have seen very little of Zonediggity.