Hello,I cepelmtoly agree that placing is so much important in terms of SEO. We should put first H1 then H2 and then H3 tag. Not like First H2 or H3 and then H1. GoogleBot reads content as per Google?s guidelines and it can only crawl your website when things are proper in place. Like Header text, Alt tag and some other optimization is also important as per Google?s point of view.It's not essential to use content source ordering, as Google will crawl your site as normal without it. But it does help in terms of ranking.