Hi Tori -- you're correct. If you want to add it to the stream in any place, simply drag, drop and activate. If the emails are greyed out, they're most likely deactivated (you can confirm by hovering over the email in the stream and clicking the tool icon). If they're not active and you add a new email, the placement doesn't matter as long as those emails stay deactivated -- Marketo will search for the active email to send. Keep in mind that if you do decide to reactivate them, the order in which the emails will be cast.