You're on the right track. However, lexical variables' scope is delimited by the blocks. package does not make a new scope.

Consider:

{
    package Foo;
    my $foo;
}
{
    package Bar;
    my $foo; # new $foo not to be confused with one above
}
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Versus:

package Foo;
my $foo;

package Bar;
my $foo; # my declaration masks previous one
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