https://translatewiki.net/wiki/MediaWiki:Apihelp-compare-summary/en-gb is not a translation of https://translatewiki.net/wiki/MediaWiki:Apihelp-compare-summary/en

We shouldn't just be replacing two with 2 for example.

Or add a trailing : or .

en-gb is littered with many pointless translations, but the process of getting rid of them is awkward. You have to remove them from the repo and delete from translatewiki

The same goes for translations not in english etc, or identical to en.

I've removed ~750 translations in mw core from mostly en-gb today... It's such a mess