As a several decades coach - and longer than that competitive distance runner - I have full sympathy for the O.P. If you run a race, you should always expect to give 100%. Only a kid who is far better than his competition can train through a race. And middle distance and distance races are tough mentally and physically.
Dual and tri meets usually last 2-3 hours. I would never ask an athlete to race the 1600, 800, and 3200 in that time frame. Even at State, where the 4x8 use to be in early afternoon and the 1600 and 3200 was at night, I never asked a kid to triple. The only kid I coached who ever did so was Billy Convey, a 4:08.3 miler (2nd at Golden West) and an 8:57.5 2 miler (still the Florida Relays record after 35 years). He wanted to triple at State to try to break Class 2A records set by Scott Scheffler of Clewiston. He succeeded. Barely. By a total of 3.0 seconds for all three races. In under two hours. (In other words, he had to go all out.) Yet in the last, he ran just 9:23.4 in the 2 mile. 25.9 seconds slower than his Florida Relays record. The first call for that race came while he was on the track waiting for the stick to anchor our Sprint Medley. Billy was by far the fastest runner I ever coached and he was also probably the toughest competitor. But at the end of a triple, in a short time frame, he was far off his P.R. It was a unique opportunity. He wanted to do it.
Asking any kid to triple repeatedly is in my view absurd. The coach can have no comprehension of what it means to give an all-out effort. It is also stupid. Many kids will find something else to do with their afternoons rather than run for such a coach.