Please be informed the workflow you are following is called Sequential Signing. Single document is Signed by multiple Signers in the sequence you enter the email addresses in the recipient field.
The feature you are requesting for is called Mega Sign feature in which a single document is send to Multiple Signers, they individually Sign the document & send them back to you. So it's like you Sign one document to Multiple Signers & received Multiple Signed copies.
This feature is only available in Adobe Sign Business & Enterprise accounts: