Tough Q's to answer there. My shotguns are (12ga.) purpose purchases. One for trap (Browning XT) one for International skeet (Beretta 687EELL it's FAST from the hip line) American skeet (Beretta AL390 Gold Mallard always low mount) and 5 stand (Miroku 500 SxS I like the traditional thing)
Can I shoot more than one discipline with only one shotgun? Yup but I don't have to, I no longer have a wife
Anyway... if I had to the EELL would do everything but trap, if I did not have that, the 390 would do but only one choke would hurt (I'm just not THAT good) 5 stand. I have not shot SC, it never interested me.
I've had Browning field grade O/U's but I shot the Beretta EELL better.