When you fly students 2 or 3 times a day, it adds up. I'm not sure I ever did that outside of a XC in Navy training. I'm not for or against AF or Navy briefing styles, both have their merits, but I think the way they brief lends itself to multiple X's per day more than our briefs do. ?♂️
I've seen a few different things tried to improve production in Navy primary and advanced training. I still think it comes down to institutional willpower and deciding what you want a student's primary flight training experience to look like.
The traditional primary model is one IP and one student, brief-fly-debrief. That one-on-one puts a lot of pressure on the student during the brief and that is a good thing. You have zero sense of moral support from your stick buddy when you don't know something, it's just you and the IP in that lonely cubicle.
It would be more efficient to brief two students at a time, then come back a few hours later for the second one- we did that during one of the primary training dets out to the desert several winters ago when we were suddenly short half our airplanes due to emergent maintenance issues (there's a shocker...) and of course we did get much better utilization out of the remaining airplanes.
Briefing two students at a time (or three) is also the standard model for advanced helicopter training. For slightly more brief time you save a bundle later when you hot seat (swap) the students. Speaking of aircraft availability issues, after the freak hail storm one spring weekend in 2005, we were down to something like a 10-20 aircraft each day and we were running those continuously for I think 12 hours at a time (in-house rule for the circumstances, shutdown NLT 12 hours to check the tail gearbox oil level). A few of the guys on the helo trainer thread will remember that one.
Back to primary training, hot swapping students is impossible since it's prohibited to open the T-6 canopy while the engine is running, and getting the thing shutdown and started back up again is time consuming. Even if you could swap the students out, hot refueling is impractical since the fuel point being between the wing and propeller is ummmm less than optimal... woops, thanks again, T-6
design committee. (There are a lot of very smart serviceability/maintainability features built into the T-6 but the myth of hot refueling is not one of them.)
So like both of us are saying, there are merits to each way of producing students.