What makes you think they might be equivalent?

*{$x} = sub {};
[download]

is no more equivalent to

&{$x} = sub {};
[download]

than

*{$x} = [];
[download]

is equivalent to

@{$x} = [];
[download]

In the first, you assign to a symbol table entry.
In the second, you assign to a function call (or array).