By default, speakers appear in the order they were added to the session.
If you want to change that order, simply use the little tool next to the recycle bin icon to move speakers up or down the list, on "Event Data >Sessions," session concerned, Tab 2 "Speakers."
If you want to change that order, simply use the little tool next to the recycle bin icon to move speakers up or down the list, on "Event Data >Sessions," session concerned, Tab 2 "Speakers."

Your speakers have different types, you can simply reorder them as well under "People > People Settings > Type." Move values up/down as needed.