For what its worth, I may have a possible 'solution' to this problem, just something I've noticed when playing (and if someone can confirm this, wonderful!).
Each status on your friends list has friends listed alphanumerically from 1-Z. But Red & Green statuses each yield 2 sets of alphanumeric lists, seen clearly when one has many friends active. For Green, I've surmised that the upper set is folks active but not playing while the lower set is people playing a round. Same for Red, the lower set is folks actively playing a single-play or multiplayer round, the upper set being the 'I'm not playing but don't bother me' crowd.
Hope this was helpul without being too confusing.