Headers have significant bottom margins and no top margin per https://github.com/jenkinsci/jenkins/blob/04b46d1c68513e4a105b5acdfb7534c89da94eea/war/src/main/less/base/typography.less#L54-L55

The last paragraph in a sequence (e.g. inside a wrapping div) has no bottom margin per https://github.com/jenkinsci/jenkins/blob/04b46d1c68513e4a105b5acdfb7534c89da94eea/war/src/main/less/base/style.less#L575-L578

Headers should be closer to their related paragraphs than to unrelated content, that's not the case here. Especially the case of usage stats help look terrible, with no distance between a paragraph and an unrelated header. But even inline help, as well as basic HTML markup for descriptions, don't look good with these rules.