I would put them in the same release group. It helps with display, tagging, and browsing. Splitting just helps with pedantry but nothing practical imo (said with love, I often <3 pedantry!)
However I don’t think there is any consensus, and it comes up every few years… See two very recent long-ass discussions with @takerukoushirou and @ApeKattQuest_MonkeyPython:
https://musicbrainz.org/edit/83270273
https://musicbrainz.org/edit/84334755
I think it is still, for better or for worse, left up to the editor to make the call, as of 2021-12.