We lay things out from left-to-right, top-to-bottom when we share. However, only the artboards that are connected to the home artboard are included in the list. Are you seeing something different?
I've found simply laying out doesn't work well in practice. Think Powerpoint and page order.
Tip: When designing, my workaround is to copy the Artboards one at a time to a new document to ensure the order works (kind of a pain, but it works and doesnt take too long).