basically, if Garchen Rinpoche visits your center once or twice a year, if you have a bond with Garchen Rinpoche that is basically all you need. practicing in groups maybe helpful for some people but the work to be done is ''solitary'' or individual, meaning you have to do it yourself and ''alone''.
If the thought of demons
Never rises in your mind,
You need not fear the demon hosts around you.
It is most important to tame your mind within....
In so far as the Ultimate, or the true nature of being is concerned,
there are neither buddhas or demons.
He who frees himself from fear and hope, evil and virtue,
will realize the insubstantial and groundless nature of confusion.
Samsara will then appear as the mahamudra itself….