The attendee count you are referring to are the attendees with a payment status of ‘complete’. So for example, this event would only show 1 attendee – http://take.ms/uzYmO
If any of those additional 3 registrations have the payment status updated to complete they would be included in the count, is essential a count of attendee that have paid and will be attending the event as opposed to all attendees include those that started a registration and didn’t pay (or payment failed).
You cant change EE to include other statues in the count such as Incomplete (meaning the above would show 4) but you can set EE to set all attendees to have a default payment status of Complete if that will work for you?
Note that will mean that ANY registration made on the event will receive the confirmation emails etc.