Text Comparison seems to use my top 4 bibles, and will add the current resource if not present (or it will replace the 5th resource). Either way, the current resource does not become the base text (and text is sometimes not displayed).
If the resource is a Greek/Hebrew bible, it is compared with my top 4 English bibles, rather than my top 4 Greek/Hebrew bibles.
If the resource is a versified non-bible e.g. a commentary, why is TC on the Context menu?