If you go round in threes, then at best you spend two thirds of your time waiting for the other two to shoot the lane. Two minutes each and 25 lanes means 150 minutes.
Would it be possible - and I don't mean easy - to have two people shooting on the same lane at the same time, one on one target and one on another? The third person marshals both, then shoots alone. That would save potentially 50 minutes. Yes of course it would need some rethinking about layout at the shooting point. HFT shoot one target per post, I believe.