Ok so if I have H1, H2 and H3. Would it matter If the are in the order say H3 H1 H2 as long as they are on the page?
Order does not matter. The number just specifies the font size and importance (to the search engines). You don't have to use all of them either. You could have 1 h1 and 4 h3 or whatever.
the order do not matter as they are recognized by their number..the font size is also decided by that........and even the ranking also affected by it