Shooting your way through a strike, if you're competent and the team doesn't wipe, is 10-12 minutes. I always do most of the fights and it's consistent. Only times it's longer is when someone decides we can jump around to skip parts of the infinite forests in Glass or Grounded modifiers. Then you get stuck with a millions adds to kill by yourself. Then it's 15-20 minutes. Speedrunners have the impression they're going faster. Unless you're so good at it that you finish strikes in 8-10 minutes, you're not going any faster.