All the elders and all the teachers are busy. Those one and two-star teachers were busy with maintaining safety around Venus City and looking after that part of the danger zone.
Only those two-star teachers who have students did not have to follow that. Unfortunately, Sam got the duty to command every 2 star and one-star teacher to make sure nothing happened inside the danger zone.
Principle Markus wanted to make sure that nothing like that incident happened inside that part of the danger zone. Sam is familiar with that incident so it would be good if he takes the responsibility.
Sam did not have any problem with this, and for now, he did not think his students needed any guidance from him. Three of them are ready for the competition and he has trust in them.