The FAQ
Do Shadow attachments have two chances to attach when they come out of Shadows, once by the rules and once by the text on the card? No
The Shadows Rules Insert
"Attachment cards attach to another card when they come out of Shadows, as indicated in their text"
vs You
There is no explicit rule that says a Shadows attachment must have explanation and clarification text. It is in fact unnecessary as the rules explicitly establish that Shadows attachments function as normal attachments when coming out of Shadows. This means that its lack of clarification text means it functions as a normal attachment after coming out of Shadows and must attach to a legal target, in this case a character. Then, you trigger the response
An attachment coming out of shadows is just a card coming out of shadows, like any other. It doesn't attach to anything unless it's card text says so. It does NOT attach to a card *then* jump onto the card pulled from the dead pile, no more than any other shadows attachment must first attach to something *then* be triggered to move them to the appropriate character (have you ever put Dragon Skull on your own character first?).
I have no idea where you're manufacturing this claim that shadows attachments function like a normal attachment when pulled out of shadows; there are no such rules in the core or FAQ allowing for them to attach when they come into play from shadows. Without any text, they can not attach (as supported by the FAQ quote I've bolded).