use of h4 in templates

Hi,

I am looking at your templates and all of them are exclusively using h1 as the logo description and h4 for all other titles.

Why is there no use of h2 and h3 - and you take directly h4 tags it does not make sense to me but maybe you can explain the logic behind this structure - as so far in the websites I have made I used h1 in the logo for a general description - but then used h2 for the second most important titles and then h3 h4 h5 h6

Shouldn't I change all those h4 tags to h2 or h3 depending on how important the titles are - to have a clear Seo title tag structure?

Thanks for your answer