Looking for a strategy to optimize a big body field on a node
Using the Paragraphs module is probably the current go-to solution for a more manageable setup than a large body field. Functionally, it's right in between a single text field and completely separate nodes. It enables you to create more manageable chunks of content that replace the traditional body field. Each chunk can be simple text, or more complex things. Each "paragraph" is an entity with fields, and the node references those entities. When editing, it feels like a more focused interface. The content creator stays on the node, so the complexity is hidden in the background.

Another strength it has is good support for revisions. In fact, it requires the Entity Reference Revisions module, and its project page suggests using the Diff module.