Generally though, the common A-26 combat package was the 8 or 6 gun strafer nose, and the twin gun upper turrent.
Sometimes the duce pods were added, but usually only two. Same with rockets, the lower turrent, and the various bomb loads.
I think the 20 and 22 gun configurations were for test purposes only. And why would you need that many guns?

The nose guns alone carried @ 1600 rpg. Thats plenty for anyone.
But 350mph at 20k is still pretty slow compared to most fighters, and it's only going to be able to bring one turrent at a time to bare. And it's going to be down on the deck to put those guns to any good use (well other then ACMs

)
I'd like to see three versions myself: The level medium bomber configuration (alot faster then the B-26 but defensive guns are not nearly as effective, especially if the periscope sights are implemented.
The 8 or 6 gun strafer nose with bottom turrent flared over or removed, and the several ammunition loads for the nose guns including the 1600 rpg option (!) and the other shorter belts. Perhaps lighter ordinance or rocket option. In most ground attack missions they didn't load the bigger ordinance often and is why it often gets the "Light bomber" designation. I suppose I wouldn't want 1000lbers or 500 GP's slung under me if I was doing N.O.E. missions
Then of course the perk version, including the heavy ordinance options, both or neither turrents, rockets, gun pods, and the A-26 adaptation of the Soviet quad 20mm Hispano nose used on the A-20 on the Easterb front

The only two I can think of that would have a consistant rate of surviving arena play and thats the Ar234 and the B-29. Anything else can be chased down and shot up by the better part of the plane set.