Hi Sam -

I like how you are demonstrating genetic distance by having
students take a look at the matrices.  However, the matrix you use as
an example is inaccurate for representing microsatellite data.  There
will be two alleles/locus for a diploid species.  No matter how alleles
are distributed amoung loci, this is not possible with the current
example.  In addition, due to  this dependency A = B in the case of the Bray-Curtis (# of loci * 2, or more generally # loci * ploidy). 
I put an example below, keeping the number of alleles (6) the same as
your example.  Each letter represents a locus (X locus, 3 alleles; Y locus, 2 alleles; Z locus, 1 allele).  I suggest updating your
matrices and indicating loci in some way (color, heavy outlines,
Loc1_A/Loc1_B, etc).  AFLP data could also be represented, but would be presence/absence of alleles (0,1).

               X.1    X.2     X.3    Y.4    Y.5    Z.6       A    B    C
Bear1         1       1      0        2       0      2        6     
Bear 2        0       1      1        1       1      2              6   
Min             0       1      0        1       0      2                     4