There is a maximum of only ten comparisons. By your criteria, the OP had it right in the first place. The ternary operator, with the format from the book "Perl Best Practices", cleans it slightly.

my $match =  $RB1 == $RB2  ?  1 
          :  $RB1 == $WR1  ?  1 
          :  $RB1 == $WR2  ?  1 
          :  $RB1 == $TE1  ?  1 
          :  $RB2 == $WR1  ?  1 
          :  $RB2 == $WR2  ?  1 
          :  $RB2 == $TE1  ?  1 
          :  $WR1 == $WR2  ?  1 
          :  $WR1 == $TE1  ?  1 
          :  $WR2 == $TE1  ?  1 
          :                   0
          ;
[download]

UPDATE: Or even

my $match =  $RB1 == $RB2  ||  $RB1 == $WR1  ||  $RB1 == $WR2  ||  $RB
+1 == $TE1
         ||  $RB2 == $WR1  ||  $RB2 == $WR2  ||  $RB2 == $TE1
         ||  $WR1 == $WR2  ||  $WR1 == $TE1
         ||  $WR2 == $TE1 ;
[download]