h2 heading and h3 subheadings (info-boxes) are not in one Gutenberg block.

Hi there
I have two options. One Guttenberg block with H2 heading and h3 subheadings (info-boxes) or second option two separate blocks one for H2 heading second block for H3 subheading (info-boxes). Which method is best for SEO ? One block option (parent is heading and subheadings are children) or two blocks option one (h3 subheadings) after the other (H2 heading)?
Thank you