It's important to really use the keywords you want to rank for in h1. The others help (h2,h3), but the most important is h1. Don't let h1 be the same on all your pages
I had to fix up someone else's site recently that was built by a person who charged a lot of money for the work, and every title on every page was a h1 lol. I couldn't believe it.
With Joomla sites, you should really use template overrides. It's basically up to whoever creates the Joomla template to do their own title tags, css based layout and seo optimisation.The Joomla default template, for example, doesn't use <h1> at all, it uses <div class="componentheading">. "componentheading" has no SEO value
Most of the CMS are based on Dynamic URL creation technology and they do not create Static URL. Moreover, you can use <H1> twice of thrice in a web page which a CMS cannot do.
My CMS creates static URLs if I ask it to. Moreso, I can add as my H1 tags to my CMS as I want. But, I guess WordPress is a weird form of a CMS. Joomla, in my opinion, is garbage. Anyone who makes a Joomla site needs to have someone come in and tear the sucker apart for SEO.
There should be only one <h1> tag on every page as having more than one h1 tags it is not good for seo perceptive.
There should be only ONE <h1> tag on a webpage which should either describes your webpage or your content. Target the keyword while using <h1> tag. Google will also penalize for over optimizing your website, so properly use every element.