And Ranger subguild beast sizes are determined as follows (so far as
I can tell - asked 25-30 rangers)

Lore\Mast 1  2  3  4  5  6  7  8  9  10 11 12 13 14 15 16 17 18 19 20
   40     S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  N
   45     S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  N  N
   50     S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  N  N  N
   55     S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  N  N  N  N
   60     S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  N  N  N  N  N
   65     S  S  S  S  S  S  S  S  S  S  S  S  S  S  N  N  N  N  N  L
   70     S  S  S  S  S  S  S  S  S  S  S  S  S  N  N  N  N  N  L  L
   75     S  S  S  S  S  S  S  S  S  S  S  S  N  N  N  N  N  L  L  L
   80     S  S  S  S  S  S  S  S  S  S  S  N  N  N  N  N  L  L  L  L
   85     S  S  S  S  S  S  S  S  S  S  N  N  N  N  N  L  L  L  L  L
   90     S  S  S  S  S  S  S  S  S  N  N  N  N  N  L  L  L  L  L  H
   95     S  S  S  S  S  S  S  S  N  N  N  N  N  L  L  L  L  L  H  H
  100     S  S  S  S  S  S  S  N  N  N  N  N  L  L  L  L  L  H  H  H