What was the workout supposed to accomplish? I guess I’d ask the HJ coach that one.
If those high jumpers also run 800s or 1600s, that workout might make sense. I doubt that it would contribute anything to better HJ – other than shaving off some weight maybe. You were wise to stop it.
Running some 400s is not a bad thing because the speed of the 400 equates fairly closely to the speed at the end of an approach in HJ. I think there are better ways to deal with that, however. For example, curve running on the track with a walk back across the track to the start is good (if the runner jumps from the left side, though, they should run the curve in the reverse direction). I also would opt for more explosive activities, but the days between high intensity workouts could be tempo runs (less than 75% effort) in the 100 to 200 meter range, totaling about 1600 meters or so. It depends, too, on what other events they are doing.
It’s a little hard to get too far into this based on one workout, but that workout doesn’t seem appropriate.