Roger knew how crucial the cultivation method was on modern Earth. That was why he could see that there would be people in the near future that would try to covet the method, putting his people in danger.
However, Roger knew that it would not be too hard to negate. With the training, he could build it as well as the team-building of the founding members of the gang. And using team building, he could fortify their relationship with each other.
But, what would be the team building's use? Well, it was to take advantage of the distress signal that would warn everyone if they got into danger in the near future.
"Distress signal is important, so be sure to remember that all of you just have your backs. If I am not around, or my family is in danger, you should use that distress signal."
Fortifying their loyalty to him was the purpose of the introduction of the distress signal. Why? Well, showing that he cared for them would deeply caress their hearts.