...
my @rxs = (
    qr/\s*(\w)\s+(\w)\s*$/,
    qr/\s*(\d)\s+(\d)\s*$/,
    qr/\s*([a-z])\s+([a-z])\s+([a-z])\s*$/,
);

my @result;

for my $rx (@rxs) {
    if ($text =~ /$rx/mgc) {
        my $match = $&;
        # match again to extract submatches
        my @grps = $match =~ $rx;
        push @result, [ @grps ];
    }
}