sorting student names into teams of three

This is a follow up to help that I received a while ago on a similar question.

I have a list of students that need to sorted into teams of three persons. (see attachment - 'SHUFFLE' worksheet)

Absent students - i.e. students signified by a number (see worksheet) rather than a name need to be excluded from the sort.

I tried to do this myself by manipulating the formula I had for making pairs but got stuck pretty quickly.

Can anyone help with this.